Loading...
HomeMy WebLinkAboutJ4 Willson-College Signal Commission Memorandum REPORT TO: Honorable Mayor and City Commission FROM: Debbie Arkell, Director of Public Services Chris Kukulski, City Manager SUBJECT: Willson/College Intersection Improvements MEETING DATE: November 27, 2006 BACKGROUND: On December 5, 2005, the City Commission voted 4-1 to direct MDT to forward both a revised traffic signal design and roundabout design to the next step in the process, with preference given to the roundabout first, and a traffic signal with no eastbound left turn lane as the alternative option. The completed Design Option Comparison finds that a roundabout would have an adverse impact on the Bon Ton Historic District, and recommends that a traffic signal be installed to address crash trends and improve traffic operations at the intersection. Five public meetings have already been held on this project. There are three City Commissioners who were not on the Commission when these meetings were held and direction given, and Staff has been asked to bring the matter back to the Commission before the Montana Department of Transportation proceeds to make improvements at the intersection. City and Montana Department of Transportation Staff will be present to answer questions. Each year, the Montana Department of Transportation requests cities to submit high-accident intersections that might be eligible for the Federal Traffic Hazard Elimination Program. City staff reviews the intersection accident history reports and the 2001 Transportation Plan Update, and makes recommendations to the Department. If an intersection is selected, the Department then completes a review to determine if the intersection(s) qualifies for the funding. The 2001 Transportation Plan identifies the need for adding left turn lanes and installing a traffic signal at the intersection of South Willson Avenue and College Street, and based on this and the accident history, City Staff submitted the Willson/College intersection for consideration for the 2003 Traffic Hazard Elimination Program funding. This intersection meets four of eight signal warrants: 8-hour, 4-hour, and peak hour traffic volumes, and accident experience. Sixteen accidents resulting in 15 injuries were recorded between January1, 1999 and December 31, 2001. Twelve of the 16 accidents were considered correctible with a traffic signal. From January1, 2000 through December 31, 2002, 14 accidents were recorded. The Bozeman Police 1 Department advised MDT that during 2003 and 2004, 16 accidents were investigated at the intersection, and advised them that congested conditions on College Street occasionally inhibits emergency response times in the area. The traffic study completed in 2002 showed the Level of Service on both College Street approaches was “F”, with estimated queue lengths of 4 vehicles on the westbound approach and 13 vehicles on the eastbound approach during the peak hour. There are over 12,000 average daily trips (ADTs) on Willson south-bound; 11,800 ADT on Willson north-bound, 1,400 on College east- bound; and 440 on College west-bound. The Montana Department of Transportation held a public meeting on December 2, 2004 at the GrantTree Inn and received comments on the proposed design of a signal. A copy of the December 2, 2004 meeting transcript is available in the Director of Public Service’s office. The Department reviewed the information received, both at the meeting and in writing after the meeting, and extended the public comment period. The Department reviewed several different options, and presented those options at a City Commission work session on May 9, 2005. The options reviewed include a 4-way stop; the current 2-way stop; a traffic signal with turn lanes; and a traffic signal without turn lanes. Based on that evaluation, the Department determined a traffic signal with left turn lanes was the best alternative. Public comment was taken at this meeting, with concerns expressed regarding the impact to the historic character of the neighborhood, the amount of parking that would be removed; impact on driveways; traffic backup and air emissions. A copy of the May 9, 2005 City Commission minutes is available on the City’s website at www.bozeman.net. Based on comments heard at the May 9, 2005 meeting, MDT revised its initial design to retain as much on-street parking as practicable, and by reducing lane widths and shortening tapers they saved about 20 spaces. The design proposed keeping the left turn lane for southbound traffic because left turn movements would likely generate queues of vehicles that may shift vehicles wishing to make left turns to other intersection (i.e., through adjacent neighborhoods), and only one more parking space could be saved by dropping that turn lane. Black powder coated signal poles were also proposed. Issues raised at that meeting were the aesthetics/appearance of the light, whether left turns from Willson onto College should be eliminated; if all parking has to be eliminated; and are other options available, such as a flashing light. MDT reviewed those issues and comments and made proposed design changes that would retain about 20 parking spaces; determined restricting left turns for the southbound Willson Avenue traffic for the benefit of retaining more on-street parking was not a viable option; and proposed to provide a black powder coated signal pole to address aesthetic concerns. The revised design was presented at a special neighborhood meeting held at the Longfellow School Gymnasium on November 9, 2005, with over 60 people in attendance. This meeting provided residents within the area information regarding the revisions MDT made to the proposed stoplight design, following comments heard at the May 9 meeting. One of the most vocal issues expressed during the meeting was that the Historic Preservation review portion of the Environmental Assessment (NEPA, Category X) was not yet completed, and a decision should not be made by the City Commission to proceed with the signal until that was completed. 2 A fourth public meeting was held by the City Commission on November 14, 2005, and was facilitated by Jim Madden from the Community Mediation Center. A summary of comments and issues presented to the Department up to that date was provided to the Commission and public, and that summary is attached to this memo as Attachment “A” to provide additional background information to the current City Commission. The South Willson Improvement Association submitted a written counterproposal that included the following (a copy of the full report from the Association is on file in the Director of Public Service’s Office): • The improvement of sight distance from College Street onto Willson Avenue through the elimination of parking for only a distance of 100 feet from the intersection in all directions, but allowing for the “drop off” area on the southeast corner for the Children’s Development Center. • Enhance this intersection with landscaping, marking it as special and more visible. • Special signage, denoting Historic District, at key entrance streets such as Willson. • The elimination of the proposed turning lanes. Maintain the current lane width for through traffic flow, safety, and parking beyond 100 feet for north and south on Willson. • The installation of “minimum cost” measures including larger stop signs and stop ahead signs along College Street, boldly alerting drivers of the upcoming intersection. • The installation of a photo-ticketing device at the intersection and the strict enforcement of the 25 mph speed limit. At this meeting, the MDT District Administrator asked the Commission to commit to whether they support the installation of a signal at this intersection, because if a signal is not supported by the commission, they will not continue their review and will dedicate their resources elsewhere. They stated if the Commission continues to support the possibility of a signal, they will continue the review, and added that the signal cannot be installed without resolving any adverse effects identified during the Section 106 Historic Preservation review. Comments were received both supporting and opposing a traffic signal, and several questions and new ideas were proposed that were further investigated by MDT. These included: Can the signal be designed with no left-turn lane for southbound Willson traffic to turn east onto College; enhance the intersection to make it more special and visible; add special signage for the historic district; eliminate the proposed turn lanes so current lane widths can be maintained; install “minimum cost” measures like larger stop signs and stop ahead signs along College Street to alert drivers of the intersection; and install a photo-ticketing device at the intersection and strictly enforce the posted speed limit. The Commission asked MDT to further research the feasibility of a signal with no left southbound turn onto College; a roundabout; the neighborhood association’s proposals; no signal with a left turn lane on Willson for north-bound traffic; and to further address driveway access issues, and to report back to them on December 5, 2005. At the December 5, 2005 City Commission meeting, the following options were reviewed by MDT: 3 1. The original proposal to install a signal with left turn pockets for both northbound and southbound Willson Avenue traffic. 2. Install a signal with no left-turn lane for southbound Willson Avenue traffic to turn east onto College Street. This would allow the parking situation to be as it exists today, with the exception of the residence on the northwest corner, and no parking would be allowed on Willson Avenue in front of that residence. 3. Install a roundabout at the intersection, which could fit if additional right-of-way is obtained at each corner. Parking would be eliminated for approximately 80-100 feet on each corner of the intersection. The designated drop off area for the Childrens Development Center may have to be moved a little further east or reduced to allow for the proper operation of the roundabout. Curb and sidewalk would have to be removed and replaced, which would include reconstruction of ADA ramps. Any costs over the benefit/cost would be the city’s responsibility. Public comment expressed support of the roundabout, the importance of preserving the character of the historic neighborhood, concern of noise and light pollution from a signal; concern the neighborhood’s plan would not allow west turns from the intersection; support of a traffic signal for safety; concern about the removal of parking. In addition, several letters both in support and opposing a signal were submitted. A copy of the Commission minutes and the packet information, including the letters received, is available on the city’s web page. At the meeting, MDT asked the Commission to take official action, noting that they have compromised as far as they can and still provide a safe intersection for the traveling public. MDT officials advised us that by giving them the direction to proceed, the funds would be committed, but if the City elected to not install any improvements, the City would be responsible to reimburse them for the design costs. On a 4-1 vote, a City Commission motion directed MDT that both the revised traffic signal and roundabout be forwarded to the next step in the process, with preference given to the roundabout first, and a traffic signal with no eastbound left turn lane as the alternative option. A Comparison of Intersection Design Options for the intersection was prepared for the Department by Robert Peccia & Associates. The entire report is available in the offices of the Director of Public Services and City Engineer, as well as on the city’s web page. The comparison includes a thorough analysis of both the signalized intersection as well as the roundabout option, and provides a detailed comparison of the signal and roundabout for: • Operational effects (LOS, queues, travel speeds, design life, would it cause traffic to shift to side streets, access to public transportation, affect on vehicular access, construction and operating/maintenance costs, special maintenance); • Effects to on-street parking and driveways (how much parking would be lost; impact on residential driveways); • Effects to sidewalks and pedestrian crossings; • Effects on traffic safety (how each would address accident trend of broadside crashes, potential for a change in the type of crashes); • Effects on pedestrian and bike safety; 4 • Environmental effects (need of right-of-way, relocation of housing or businesses, impact on utilities, is project consistent with land use plans and zoning, would design induce changes in land use and density or induce growth, impact on residents with special needs, emergency service facilities, response times, traffic noise, air quality impacts, visual impacts/aesthetics); • Social impacts/environmental justice; • Economic impacts; • Other environmental resources. • Effects to Cultural Resources With regard to effects to Bon Ton Historic District, MDT received a letter from the State Historic Preservation Officer concurring with the Study’s determinations that the signalized intersection option would have No Adverse Effect on the District, and that the roundabout design would have an Adverse Effect to the District. The factors supporting the determination of a roundabout (RAB) having an Adverse Effect on the District include: • RAB would be an entirely new form of intersection treat in the Bon Ton Historic District. There is no precedent for the use of a RAB in an historic district in Bozeman; • Because of the design features, the RAB would be significantly different from the existing streetscape by placing a round feature within an historic grid pattern street system; • The RAB would require substantial amounts of new r/w at each of the four quadrants of the intersection. The circular configuration of the RAB would result in the reconstruction of sidewalks and boulevards at the intersection to make them conform to the new layout. This would also be a deviation from the traditional grid pattern of the historic district and result in wider boulevards and sidewalks located closer to historic properties built to conform to the RAB; • Approximately 9 to 12 mature trees located in the boulevards but associated with the historic properties would have to be removed. The mature trees in the boulevards have historically provided a screen between the historic properties and the street and, more importantly, helped define the historic character of the historic district. Their loss would significantly change the appearance of the neighborhood. • Two historic lampposts would have to be relocated, which would upset the staggered configuration and spacing between other lampposts on Willson Avenue in the historic district; • Additional street lighting would have to be added to the intersection to make the RAB safer. The RAB would also require significantly more regulatory and guidance signage on each approach. • Considered together, these impacts and the addition of modern street features would significantly diminish the historic character and appearance of the neighborhood. In summary, the report found the project is a safety improvement designed to address crash trends and improve traffic operations at the intersection. Based on the results of the study finding that the roundabout would have an Adverse Effect to the historic district, while a signal has No Adverse Effect, MDT plans to move forward with the design of a signalized intersection 5 at this location. If a signalized intersection treatment is no longer the City’s preferred option, the City will be required to reimburse MDT’s costs to date, which are estimated at $82,000. RECOMMENDATION: That the Commission confirm the decision to install a traffic signal at the intersection of College and Willson, through the use of Federal Hazard Safety Elimination funding. FISCAL EFFECTS: Installation of a signal would likely have minimal, if any, fiscal effects, as the entire cost of the signal would likely be funded through the Traffic Safety Hazard Elimination program. If a roundabout were installed, the City would be responsible for the entire cost, including right-of-way purchases, because federal funds could not be used for a project that has been identified as having an adverse effect on the historic district. ALTERNATIVES: As suggested by the City Commission. Respectfully submitted, _________________________________ ____________________________ Debbie Arkell, Director of Public Services Chris A. Kukulski, City Manager Attachments: Attachment “A”, MDT 9/23/05 letter with attachments Report compiled on ________ 2004 6 COMPARISON OF INTERSECTION DESIGN OPTIONS FOR SOUTH WILLSON AVE./COLLEGE ST. 2002-COLLEGE STREET SIGNAL-BOZEMAN STPHS 1209(2); Control No. 5376 September 2006 Prepared for: Montana Department of Transportation Environmental Services Bureau Prepared by: Robert Peccia & Associates, Inc. 2002-COLLEGE STREET SIGNAL- BOZEMAN STPHS 1209(2); CN 5376 COMPARISON OF DESIGN OPTIONS i TABLE OF CONTENTS PART I: Introduction and Background A. Project Setting ............................................................................... 1 B. Need for the Project ....................................................................... 2 C. Project Issues................................................................................. 3 D. Existing Configuration and Traffic Controls ......................................... 4 E. Traffic Volumes............................................................................... 5 F. Functional Classification .................................................................. 5 G. Accident History and Trends............................................................. 5 H. Existing Level of Service .................................................................. 6 I. Signal Warrants.............................................................................. 6 J. Other Operational Considerations ...................................................... 7 PART II: Designs Under Consideration A. Signalized Intersection Design .......................................................... 8 B. Single Lane Modern Roundabout Design........................................... 10 Part III: Comparison of Design Options A. Operational Effects........................................................................ 12 B. Effects to On-Street Parking and Driveways...................................... 22 C. Effects to Sidewalks and Pedestrian Crossings................................... 24 D. Effects on Traffic Safety................................................................. 26 E. Effects on Pedestrian and Bicycle Safety........................................... 27 F. Environmental Effects .................................................................... 29 1. Right-of-Way and Utilities....................................................... 29 2. Land Use Effects ................................................................... 30 3. Traffic Noise......................................................................... 34 4. Air Quality Impacts ............................................................... 35 5. Visual Impacts/Aesthetics ...................................................... 36 6. Social Impacts/Environmental Justice ...................................... 39 7. Economic Impacts................................................................. 41 8. Effects to Other Environmental Resources................................. 43 Part IV: Effects to Cultural Resources A. Effects to the Bon Ton Historic District ............................................. 44 1. Impacts to Street Trees ......................................................... 52 2. Impacts to Historic Street Lights ............................................. 53 B. Effects to Historic Properties at the Intersection ................................ 55 1. Potential Effects to the Story Mansion ...................................... 55 2. Effects to Other Properties...................................................... 57 C. Section 106 Considerations ............................................................ 59 D. Section 4(f) Considerations ............................................................ 62 E. Local Historic Preservation Considerations ........................................ 63 ATTACHMENT 1: Supplemental Capacity Analyses ATTACHMENT 2: SHPO Letter Concurring with Determinations of Effect for Signal and Roundabout Options COMPARISON OF DESIGN OPTIONS -1- PART I: Introduction and Background A. Project Setting The intersection of South Willson Avenue and College Street is located in the south central portion of the City of Bozeman in a residential neighborhood. The intersection is situated some six blocks south of the downtown area and about five blocks east of the Montana State University campus. The blocks immediately north of the intersection consist almost entirely of single-family homes. However, the Sigma Chi Fraternity house, a multi-family residential use, exists on the northeast corner of the intersection. The Children’s Development Center is operated from a residence located at the southeast corner of the intersection. Willson Avenue and College Street are designated Urban routes, U-1209 and U-1210, respectively. Willson extends from its intersection with Kagy Boulevard (located about 0.7 miles south of the College-Willson intersection) to Durston Road located more than a mile north of the intersection. College Street begins at Huffine Lane (about 1.6 miles to the west) and ends several blocks east of Willson. The location of the project area is shown below. COMPARISON OF DESIGN OPTIONS -2- The College-Willson intersection is also situated in the Bon Ton Historic District, a historic district listed on the National Register of Historic Places (NRHP). The Historic District (shown below) is generally bounded by Olive Street to the north, Cleveland Street to the south and Fourth Avenue to the west. The eastern boundary of the District encompasses properties adjoining the east side of South Willson Avenue but does not extend to South Tracy Avenue. The Bon Ton Historic District includes some of Bozeman’s finest examples of historic residential architecture styles and consists of 189 contributing and primary buildings. Three buildings that contribute to the historic district are located at the College-intersection: the Story Mansion (811 South Willson) at the southwest corner; the Stewart House (804 South Willson) at the southeast corner; and the E. W. King House (725 South Willson) at the northwest corner of the intersection. B. Need for the Project This proposed project is a safety improvement designed to address crash trends and improve traffic operations at the intersection of Willson Avenue and College Street. The Greater Bozeman Area Transportation Plan 2001 Update, adopted by the Bozeman Transportation Coordinating Committee in May 2001, identified the need for adding left turn lanes and installing traffic signals (when warranted) at various intersections in the community. Implementing such improvements at the intersection of Willson Avenue and College Street was included in the Transportation Plan and identified as Transportation System Management project (TSM-33). The justification for the project presented in the Transportation Plan was that the intersection met multiple signal warrants, most notably the warrants for 8-hour, 4-hour, and peak hour traffic volumes and accident experience. In 2002, the City of Bozeman hired Marvin & Associates, a traffic engineering consultant, to look at various intersections within the City including the Willson Avenue-College Street intersection. The preliminary engineering study done by the City’s consultant in March 2003 provided updated traffic volume and accident data for the intersection and a new signal warrant analysis. Several options for traffic control at this intersection were also considered including: 1) the current situation (stop control for east and westbound motorists on College Street); 2) a four-way stop; and 3) a traffic signal with and without left turn lanes on Willson Avenue. College-Willson Intersection Project Area Location Within the Bon Ton Historic District COMPARISON OF DESIGN OPTIONS -3- Based on the evaluation, signalizing the intersection and adding left turn lanes on Willson was determined to be the best option for this intersection considering its accident history and operational conditions. During 2003, the City submitted a request to the Montana Department of Transportation (MDT) for funding for the signal project through the Federal Hazard Elimination Program. The purpose of the Federal Hazard Elimination Program is to identify hazardous locations on the states’ highway system, assign benefit-to-cost ratio priorities for the correction of these hazards, and implement projects to make the needed improvements. Hazard elimination projects are funded with 90 percent federal funds, and 10 percent state funds. Projects eligible for funding under the Hazard Elimination Program include any safety improvement project on any public road; any public surface transportation facility or any publicly owned bicycle or pedestrian pathway or trail; or any traffic calming measure. MDT’s Traffic and Safety Bureau selects the projects by identifying high hazard sites through the analysis of law enforcement accident reports. Sites with multiple accidents over time are field reviewed and a determination of an appropriate type of corrective action is made for the sites. The cost of the proposed hazard elimination project is compared with the potential benefit of the action. Once the benefit-to-cost ratio is calculated for all high hazard sites statewide, the eligible projects are prioritized from highest to lowest need. MDT approved the City’s funding request based on the expected benefit-to-cost ratio of 3.63 for installing a traffic signal. MDT began efforts during 2004 to complete environmental compliance activities and develop design plans for improvements at the intersection. Although College and Willson are city streets, MDT is the “lead” on the project because the streets are on the state’s Urban system, federal and state funds are involved, and the agency possesses the technical expertise needed to design the improvements. However, MDT is developing the project based on overall design direction from the City of Bozeman. C. Project Issues As initially proposed, the project included the installation of a semi-actuated traffic signal and the addition of left turn lanes for northbound and southbound traffic on Willson Avenue. MDT held a public meeting on December 2, 2004 and received numerous oral and written comments on the design proposal. The comments focused on the following issues or concerns (not in any order): o The public’s need for more time to submit comments on the proposal; o Negative effects on the operation of the local street network after signalization (i.e., the project would attract more traffic, result in longer delays and vehicle queues, increase travel speeds on Willson); o Removing pedestrian bulb-outs would make the intersection less safe for pedestrians; o The loss of on-street parking would be a hardship for residents and visitors in the area, as well as a daycare and fraternity houses in area; o Difficulties for residents to get in and out of their driveways; o The traffic signal would be out of character for the historic neighborhood; o The proposed improvements would encourage the transition from residential to commercial uses in this area; and o Potential degradation of property values (presumably due to the above factors). The proposed design for the intersection was discussed again at the Bozeman City COMPARISON OF DESIGN OPTIONS -4- Commission meeting held on May 9, 2005. The principal comments heard at that meeting were related to the potential loss of on-street parking; the restriction of southbound left turns for the benefit of retaining parking; and the potential adverse effects to the character of the historic district. Based on the comments heard at the May 9 meeting, MDT revised its initial design proposal to retain as many on-street parking spaces as practicable. The revised design used reduced lane widths and shorter tapers which saved about 20 on-street parking spaces. MDT proposed keeping the left turn lane for southbound traffic because left turn movements would likely generate queues of vehicles that may shift left turns to other intersections and only one more parking space could be saved by dropping the turn lane. Incorporating black powder coated signal poles was also suggested as a way to make the signal more compatible with its surroundings. The revised design for the intersection was presented at a special Neighborhood Meeting on November 9, 2005 and at the November 14, 2005 City Commission Meeting. Many of the comments heard at the meeting were similar to those previously made about the signalization proposal. However, several questions and new ideas were proposed that were further investigated by MDT: o Can the signal be designed with no left-turn lane for southbound Willson traffic to turn east onto College? o Can a roundabout be designed to fit into this intersection? o Are neighborhood proposals for the intersection viable actions? These proposals included: ƒ Improving sight distance at the intersection through the elimination of parking; ƒ Enhancing the intersection to make it more special and visible; ƒ Adding special signage for the Historic District in the area; ƒ Eliminating the proposed turning lanes so current lane widths can be maintained; ƒ Installing “minimum cost” measures like larger stop signs and stop ahead signs along College Street to alerting drivers of the intersection; and ƒ Installing a photo-ticketing device at the intersection and strictly enforcing the posted speed limit. MDT addressed and discussed these items at the City Commission meeting held on December 5, 2005. As a result of the meeting, MDT was directed to further investigate two design options that would mitigate the existing crash trend at the intersection--a signal with a left-turn lane only for northbound traffic on Willson and a roundabout. D. Existing Configuration and Traffic Controls Willson Avenue is 45.5 feet wide from back-of-curb to back-of-curb. College Street has a back-of-curb to back-of-curb width of about 29 feet on the west side of Willson and is 34.5 feet wide east of the Willson. The existing four-way intersection has stop controls on College Street and there are no designated left turn lanes for northbound or southbound traffic on Willson. Sidewalks and tree-lined boulevards exist along both sides of Willson and College. The existing intersection has one designated pedestrian crossing on Willson located just north of the intersection. The crosswalk has advanced signing and pavement markings. Pedestrian COMPARISON OF DESIGN OPTIONS -5- bulb-outs, identifying crossing locations on Willson, exist on all the corners of the intersection. South Willson Avenue and College Street in the project area are not part of the City’s existing or proposed Bike Route Network according to the Greater Bozeman Area Transportation Plan 2001 Update and Bozeman 2020 Community Plan. Bicyclists on South Willson Avenue and College Street must share the road with motorized vehicles since no separated bike paths or designated bicycle lanes along either street. E. Traffic Volumes Traffic count data collected by the City’s traffic engineering consultant showed Annual Average Daily Traffic (AADT) volumes of 11,800 and 12,070, respectively, for Willson Avenue north and south of the intersection and AADTs on College Street of 4,400 and 1,400, respectively, to the west and east of the intersection. These volumes are based on traffic data collected with electronic counters on all approaches during a one-week period in October 2002. Traffic data for the area showed few heavy trucks in the traffic stream. Traffic volumes on Willson Avenue are at or above the estimates of Year 2010 ADT volumes for this street shown on FIGURE 3-4 in the Transportation Plan Update. The document projects ADTs ranging from 12,200 to 13,700 on Willson Avenue by the Year 2020. Traffic at the intersection is projected to increase at a rate of about 1.3% per year over the foreseeable future based on information from the Marvin & Associates study. F. Functional Classification Willson Avenue is functionally classified as a Minor Arterial. Minor arterials connect with and support the City’s principal arterial system. Minor arterials accommodate trips of moderate length and distribute travel to smaller geographic areas. On-street parking may be allowed on minor arterials if space is available. Posted speed limits on minor arterials would typically range between 25 and 55 mph, depending on the setting within the community. According to the Transportation Plan Update, minor arterials typically carry between 5,000 and 15,000 vehicles per day. College Street is functionally classified as a Collector. Collector streets provide for the movement of traffic from the arterials to ultimate destinations in residential, business, and industrial areas in the City. The collector streets also serve to channel traffic from local residential streets onto the arterial system. On-street parking is usually allowed on most collector streets if space is available. Posted speed limits on collectors typically range between 25 and 45 mph. The Transportation Plan Update indicates collector streets typically carry between 2,000 and 10,000 vehicles per day. G. Accident History and Trends Marvin & Associates study included an accident analysis for the intersection of Willson Avenue and College Street during period between January 1, 1999 and December 31, 2001. The analysis showed a total of 16 accidents at the intersection including 9 right angle accidents, 2 rear end collisions, 4 left turn opposite direction collisions, and one accident involving a pedestrian crossing Willson Avenue. Only 2 accidents occurred during hours of darkness and only 3 accidents occurred when weather and road conditions were not clear COMPARISON OF DESIGN OPTIONS -6- and dry. There were no fatalities recorded at the intersection but a total of 15 injuries resulted from 6 accidents during the three-year period. A review of the accidents showed that 12 of the 16 accidents could be considered correctible with a traffic signal. An updated accident analysis was completed for the time period between January 1, 2000 and December 31, 2002. During this three-year period, a total of 14 accidents were recorded at this intersection including 10 right angle collisions, 3 rear end collisions, and one left turn opposite direction collision. Comments received from the Bozeman Police Department, Department of Public Safety following the December 2004 public meeting, reinforced concerns about safety at this intersection. The Department indicated that 6 and 10 accidents, respectively, were investigated at the intersection during 2003 and 2004. It was also noted that congested conditions on College Street occasionally inhibits emergency response times in the area. Based on the accident data reviewed for this project, most of the accidents are right angle accidents cased by drivers on College Street failing to yield to traffic on Willson Avenue. The high volume of traffic on Willson Avenue is the main reason for problems at the intersection. Due to these high volumes, motorists on College Street cannot always find suitable gaps to cross over or onto Willson Avenue, which leads to impatience and unsafe turns. H. Existing Level of Service Level of service for intersections is typically rated from LOS A (the best operating conditions with the least delay) to LOS F (the worst operating conditions and the most delay). LOS F typically occurs when there are not enough gaps of suitable size on the major street (Willson Avenue in this case) to allow stopped vehicles on the minor street (College Street) to safely cross through traffic on the major street. Long delays and queuing on the minor street approaches are indicative of LOS F conditions. Marvin & Associates analyzed the capacity of the intersection and determined the northbound and southbound approaches on Willson operate at LOS A. However, field observations by the City’s consultant showed that lengthy queues form on Willson any time left turn movements are made during the peak travel times. It was determined that both College Street approaches operate at LOS F during the peak p.m. hour due to the length of delays for vehicles waiting to turn onto Willson. The analysis estimated queue lengths of 4 vehicles on the westbound approach and 13 vehicles on the eastbound approach during the peak hour. I. Signal Warrants Signal warrants, the nationally-accepted minimum conditions that must be met in order for a traffic signal to be considered at an intersection, are identified in the Manual of Uniform Traffic Control Devices. An intersection must meet at least one warrant to be a candidate location for a traffic signal. Failure to meet any warrants indicates a signal should not be installed and other means of traffic control may be better suited for the intersection. The Greater Bozeman Area Transportation Plan 2001 Update indicated the intersection of Willson Avenue and College Street met multiple signal warrants, most notably warrants for 8-hour, 4-hour, and peak hour traffic volumes and accident experience. The preliminary engineering study by the City’s consultant provided updated traffic volume and accident data for the intersection and completed a new signal warrant analysis. The engineering COMPARISON OF DESIGN OPTIONS -7- study indicated that 4 of 8 signal warrants were met at the intersection including those for 8-hour and 4-hour vehicle volumes, peak hour volumes, and crash experience. J. Other Operational Considerations The Sigma Chi Fraternity house, a multi-family residential use, exists on the northeast corner of the intersection. A parking area behind the Sigma Chi house is accessed from College Street east of Willson. The Children’s Development Center is operated from a residence located at the southeast corner of the intersection. There is a No Parking/Loading Zone on the south side of College east of Willson adjacent to the daycare facility. The Bobcat Transit System provides transportation to students, faculty and staff of Montana State University on weekdays during fall and spring semesters. According to a recent schedule for the transit system, the northeast corner of the intersection (Sigma Chi house) is a designated stop. COMPARISON OF DESIGN OPTIONS -8- PART II: Designs Under Consideration Two design options have been identified which would mitigate existing crash patterns and operational issues at the College-Willson intersection – a signalized intersection with left turn lane for northbound traffic on Willson and a single lane modern roundabout. These design options are described and evaluated with respect to a variety of considerations on the following pages. A. Signalized Intersection Design Traffic signals are used to control traffic flow at intersections with high traffic volumes where there are not sufficient gaps in opposing traffic flow to safely complete desired movements. Signals offer the maximum degree of traffic control at intersections and provide for the orderly movement of conflicting traffic by alternately assigning the right-of-way to various traffic movements. When properly timed, a signal can increase the traffic handling capacity of an intersection and can be valuable devices for improving the safety and efficiency of both pedestrian and vehicular traffic. The signalized intersection design proposal would install a new traffic signal and modify the College-Willson intersection. The traffic signal would be semi-actuated with protected- permitted left turn phasing for northbound traffic on Willson Avenue. A left turn lane would be added on Willson Avenue for northbound traffic. Detector loops would be installed on College Street and in the left turn lane on Willson Avenue. The curb bulb-outs would be removed at all four corners and the curb radius on the west side of Willson at College would have to be modified more than normal to accommodate turns by school busses. The parking situation would be as it exists today, with the exception of the residence on the northwest corner, where no parking would be allowed on Willson Avenue due to a westerly shift in the southbound driving lane. The lane shift would also result in a loss of some parking along Willson in front of the Story Mansion. No new right-of-way would be needed for the signalized intersection proposal. The project would include revisions to existing lighting and electrical service and minor tree trimming to avoid conflicts with new signal poles and mast arms. A drawing for the proposed signalized intersection is shown as FIGURE 1. COMPARISON OF DESIGN OPTIONS -9- FIGURE 1: Signalized Intersection Layout Story Mansion Residence/Daycare Residence Sigma Chi Fraternity House Residence COMPARISON OF DESIGN OPTIONS -10- B. Single Lane Modern Roundabout Design The Federal Highway Administration (FHWA) describes a modern roundabout as “a circular intersection that features channelized approaches, yield control for entry into the circular lanes, and approach geometry that assures vehicle speeds will be less than 30 mph.” Traffic can continuously flow through the intersection, resulting in higher capacity than a similar sized signalized intersection and lower vehicle delays. The number of potential vehicle conflict points are reduced as compared to a typical intersection and limited to sideswipes, making any accidents that do occur less severe. Typical features of modern roundabouts are shown below. MDT’s proposed roundabout design has a 100-foot inscribed diameter. The inscribed diameter is the measured distance between the outer edges of the circulatory roadway for the roundabout. According to the FHWA’s Roundabouts: An Informational Guide (FHWA-RD- 00-67, June 2000), this design falls at the upper limits of an urban compact roundabout (80 to 100-foot inscribed diameter) and the lower limits of an urban single lane roundabout (100 to 130-foot inscribed diameter). Roundabouts have raised splitter islands on all approaches. Splitter islands are an essential safety feature, required to separate traffic moving in opposite directions and to provide refuge for pedestrians. Splitter islands provide shelter for pedestrians; help in lowering the entry speed; guide vehicles into the roundabout; and deter left-turners from taking “wrong way” short cuts through the roundabout. The roundabout would fit the existing intersection but additional right-of-way would be needed at all four corners. The roundabout can only pass a large truck traveling north- south or east-west. Left turns can only be made by a 40-foot bus and single unit trucks. Parking will have to be restricted for approximately 80-100 feet on each corner of the intersection. The designated drop off area for the Children Developmental Center may have to be moved a little further east to allow for the proper operation of the roundabout but it can remain as a loading and unloading zone. Curb and sidewalk would have to be removed and replaced, which would include reconstruction of handicapped ramps. A schematic drawing for the roundabout is shown as FIGURE 2. COMPARISON OF DESIGN OPTIONS -11- FIGURE 2: Single Lane Modern Roundabout Design Residence/Daycare Sigma Chi Fraternity House Story Mansion Residence Residence COMPARISON OF DESIGN OPTIONS -12- PART III: Comparison of Design Options A. Operational Effects The existing four-way intersection has stop controls only on College Street (the east and west legs). There are no designated left turn lanes for northbound or southbound traffic on Willson. As indicated earlier, AADT volumes on Willson Avenue in the vicinity of the intersection exceed 12,000 vehicles and AADTs on College are about 4,400 west of the intersection and around 1,400 east of Willson. What operational benefits would typically be expected from each design option? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Signals offer the maximum degree of traffic control at intersections and provide for the orderly movement of conflicting traffic by alternately assigning the right-of-way to various traffic movements. They interrupt traffic flows on the most heavily traveled legs of the intersection to permit the crossing of minor movements that could not otherwise safely move through the intersection. Traffic signals assign right-of-way to conflicting movements of traffic by allocating green time to various vehicle movements (signal phases). When properly timed, a signal can increase the traffic handling capacity of an intersection and can be valuable devices for improving the safety and efficiency of both pedestrian and vehicular traffic. A major objective for the proposed traffic signal design is to maintain the free flow of traffic. The semi-actuated signal proposed by MDT would employ loop detectors only on the College Street approaches. Traffic on Willson Avenue would only be interrupted to allow College Street traffic to safely enter the intersection only when the detector is activated. Traffic can continuously flow through the intersection, resulting in higher (some studies say 30-50% more) capacity than a similarly sized signalized intersection and less vehicle delays. Traffic is not required to stop – only yield – so the intersection can handle more traffic than a signalized intersection in the same amount of time. Roundabouts offer the following main operational advantages over conventional signalized intersections: • Reductions in the speed of vehicles entering the intersection making it easier to choose an acceptable gap for merging into traffic; • Lower speeds through the intersection results in less severe crashes with less serious injuries. • Left turns are completely eliminated. • The larger curb radius improves maneuverability for vehicles turning at the intersection. • Motorists use a simplified decision- making process due to the one-way traffic flow and yield-at-entry operation; • A reduced number of conflict points when compared to a conventional intersection. • A potential for improved pedestrian safety results from shorter crossing distances, fewer possibilities for conflicts with vehicles, and lower vehicle speeds. COMPARISON OF DESIGN OPTIONS -13- How would each design option affect the Level of Service (LOS) at the time of installation and in the future? Level of service is typically rated from LOS A (the best operating conditions-least delay per vehicle) to LOS F (the worst operating conditions-most delay per vehicle). LOS F typically occurs when there are not enough gaps of suitable size on the major street (Willson Avenue in this case) to allow stopped vehicles on the minor street (College Street) to safely cross through traffic on the major street. Long delays and queuing on the minor street approaches are indicative of LOS F conditions. The following table shows the upper limit of delay associated with each level of service for signalized and unsignalized intersections. Level of Service (LOS) Unsignalized Intersection Signalized Intersection A < 10 seconds < 10 seconds B < 15 seconds < 20 seconds C < 25 seconds < 35 seconds D < 35 seconds < 55 seconds E < 50 seconds < 80 seconds F > 50 seconds > 80 seconds At unsignalized intersections, LOS E and F are often accepted for low to moderate traffic volumes where the installation of a traffic signal is not warranted by the conditions at the intersection or the location is undesirable for signalization for other reasons (i.e., the close proximity of an existing traffic signal or the presence of a convenient alternative route). For signalized intersections, level of service and average delay relate to all vehicles using the intersection. Willson currently operates at LOS A with side street approaches (College Street) operating at LOS F due to the length of delays for vehicles waiting to turn onto Willson. SIGNALIZED INTERSECTION MODERN ROUNDABOUT The proposed project would result in an overall improvement in the operation of the Willson Avenue-College Street intersection. The 2003 study by Marvin & Associates showed that the LOS on Willson Avenue would decrease from LOS A (free-flow conditions) to LOS C by the Year 2014 with left turn lanes on Willson and delays associated with the signal operation. The LOS on the College Street approaches would be improved to LOS C with the installation of a signal. RPA performed a capacity analysis of MDT’s revised signalized intersection (left turn lane for northbound traffic on Willson only) using evening peak hour data from the Marvin & Associates study. The analysis showed that overall, the intersection would operate at LOS C based on 2002 and 2014 traffic conditions. The capacity of roundabouts is greater than the capacity of signalized intersections because there are no yellow and red delay and stop times. Vehicles do not have to stop at a roundabout intersection unless another vehicle is approaching from the left within the roundabout. The gap size needed to merge into a roundabout intersection is also less than at a signalized intersection because traffic is moving more slowly. A recent research publication titled Design and Safety of Modern Roundabouts by Virginia P. Sisiopiku and Veera P. Gunda, summarized the results of literature reviews and simulation modeling comparing the operation of unsignalized, signalized and roundabout intersections under varying hourly approach volumes and percent left turn movements. The indicated that vehicles delays under various approach volumes and proportion of left turn are substantially less COMPARISON OF DESIGN OPTIONS -14- The following LOS results were determined for individual movements at the College- Willson intersection: Movement 2002/2003 LOS 2014 LOS NB LT B B NB Thru/RT C C SB LT/Thru/RT C D EB LT/Thru/RT C C WB LT/Thru/RT B B A summary of the capacity analyses and worksheets can be found in Attachment 1. with roundabouts when compared to unsignalized and signalized intersections. The delay savings become more significant as approach volume increases. The analysis also suggests that roundabouts perform better with respect to delay and LOS in all cases examined, when compared to the traditional signalized and unsignalized intersections. Several recent studies have shown superior operational efficiencies for roundabouts as compared to traditional signalized intersections. A Kansas State University study for one roundabout showed statistically significant reductions in several Measures of Efficiency including: a 14.1% drop in queue length, a 34.4% decrease in maximum approach delay, and a 33.3% decrease in proportion of stopped vehicles at the intersection. (E.R. Russell, G. Luttrell, M. Rys, Roundabout Studies in Kansas, Kansas State University, 2002) The Russell, Luttrell, and Rys study compared before and after delays at various intersections in Kansas, Maryland and Nevada, showed that installation of roundabouts reduced the amount of traffic having to stop at intersections, resulting in an overall 20% reduction in the amount of delay. RPA performed a capacity analysis for the roundabout option using ARCADY 5.0 and evening peak hour data from the Marvin & Associates study. The analysis showed that overall, the roundabout would operate at LOS A and LOS B, respectively, under 2002 and 2014 traffic conditions. A summary of the roundabout capacity analysis and ARCADY worksheets are provided in Attachment 1. COMPARISON OF DESIGN OPTIONS -15- Would the design option result in vehicle queues at the intersection? The Highway Capacity Manual 2000 (HCM 2000) defines a queue as: “A line of vehicles, bicycles, or persons waiting to be served by the system in which the flow rate from the front of the queue determines the average speed within the queue. Slowly moving vehicles or people joining the rear of the queue are usually considered part of the queue.” Vehicle queuing is an important measure of effectiveness that should be evaluated as part of all analyses of signalized intersections. Estimates of vehicle queues are used to determine the amount of storage required for turn lanes and to determine whether impacts would occur at upstream driveways and intersections. Approaches that experience extensive queues also are likely to experience more rear-end collisions. Field observations show that lengthy queues form on Willson whenever left turns are made by northbound or southbound traffic. Based on data collected by the City’s traffic engineering consultant, queues 13 vehicles long on College Street west of the intersection and 4 vehicles long east of the intersection were calculated during peak hours at the intersection. Observations also indicate that when long queues are experienced on College Street, eastbound traffic often diverts to other east-west streets when vehicles are backed up past the alley west of Willson. SIGNALIZED INTERSECTION MODERN ROUNDABOUT The analysis by Marvin & Associates indicated that maximum queues of 9 vehicles long would be expected on South Willson Avenue during the peak hour in the design year (2014) with signalization and northbound and southbound left turn lanes. RPA’s capacity analyses for the revised signalized intersection layout calculated maximum queue lengths of 12 and 14 vehicles, respectively, for the northbound through/right lane and for the southbound left/through/right lane under 2002 peak hour traffic. The calculated maximum queue lengths for these lanes increased to 13 and 19 vehicles, respectively, with 2014 peak hour traffic. Queues on the west approach (eastbound on College) were calculated to be 8 and 9 vehicles long, respectively, under 2002 and 2014 peak hour traffic. Three vehicle queue lengths were predicted on the east approach (westbound on College) under 2002 and 2014 peak hour traffic. A summary of calculated queue lengths can be found in Attachment 1. Queue formation on the north and south approaches to the roundabout would not be expected to block driveways since traffic can continually move. Roundabouts may not be effective at intersections where entry flows are unbalanced. When the volume on the major road is much heavier than that on the minor road, the equal treatment of approaches may cause undue delay to the major road. Also, if the major road carries a heavy stream of through-traffic, the lack of adequate gaps in the dominant flow may prevent the minor flow from entering the roundabout. (Dr. Mohamed A. Aty, PE and Dr. Yasser Hosni, PE, University of Central Florida, State of the Art Report On: Roundabouts Design, Modeling and Simulation, March 2001) RPA’s capacity analyses for the roundabout predicted minimal queue lengths (1 or 2 vehicles) on all approaches to the roundabout under 2002 and 2014 evening peak hour traffic conditions. A summary of calculated queue lengths can be found in Attachment 1. COMPARISON OF DESIGN OPTIONS -16- How would the design option affect travel speeds? The current posted speed limits on Willson and College is 25 mph. However, residents have commented that travel speeds are routinely higher than the posted limit on Willson. SIGNALIZED INTERSECTION MODERN ROUNDABOUT The main purpose of traffic lights is to manage traffic movements at the intersection not control traffic speeds. Some drivers would undoubtedly speed up to make it through a traffic light and some may accelerate quickly after stopping for the light. Traffic signals at this intersection would require through traffic on Willson to slow and stop when the right-of-way is given to east-west movements at the intersection. This would be a notable change for drivers on Willson since traffic were not previously required to stop unless turning left or waiting for a left turning vehicle at the intersection. Because the proposed signal would be semi-actuated with loop detectors on the College Street approaches, through traffic on Willson would not have to stop unless vehicles are detected on the side street. Roundabouts force vehicles to reduce their speed upon approaching the intersection. Since a deflection (raised channelization) is typically incorporated into each approach on modern roundabouts, motorists do not have a straight path through the intersection and must reduce their travel speeds. Speed reductions can be realized at all times of day and on streets of any volume. The geometric design for a roundabouts in a setting like this is such that travel speeds on the circulatory roadway is typically less than 30 mph. Does the design option offer traffic calming benefits? The FHWA defines traffic calming as “the combination of mainly physical measures that reduce the negative effects of motor vehicle use and improve conditions for non-motorized street users.” Physical changes, usually in the vertical or horizontal alignment of the roadway, are made with the intent of altering driver behavior. The FHWA lists the following objectives of traffic calming: (www.fhwa.dot.gov/environment/tcalm/) • To encourage citizen involvement in the traffic calming process by incorporating the preferences and requirements of the citizens, • To reduce vehicular speeds, • To promote safe and pleasant conditions for motorists, bicyclists, pedestrians, and residents, • To improve the environment and livability of neighborhood streets • To improve real and perceived safety for non-motorized users of the streets, • To discourage use of residential streets by non-citizens cut through vehicular traffic. Most often, traffic calming is used in residential areas where traffic has become unacceptable because of volumes or speeds and neighborhood residents have concerns about safety, noise, comfort, and convenience. COMPARISON OF DESIGN OPTIONS -17- SIGNALIZED INTERSECTION MODERN ROUNDABOUT Signals are an obvious means of controlling traffic but they are not typically identified as traffic calming measures in literature on the subject. Traffic signals are installed only where warranted by traffic volumes, accident history, or other operational conditions. Signals are designed to enhance safety and control the flow of traffic by assigning rights-of-way to various movements. They are not intended for use as speed controls or as safety devices for non-motorized users of streets. Roundabouts offer effective traffic calming benefits since they force vehicles to reduce their speed upon approaching the intersection. Consequently, intersections generally become safer for all users, including pedestrians and bicyclists. Modern roundabout designs incorporate deflections on every approach to the intersection so that no vehicle path travels straight through the intersection without a reduction in speed. The landscaping and aesthetic features associated with roundabouts can have beneficial effects in slowing traffic and providing a safer environment for all roadway users. What is the expected design life of the installation? Design life refers to the expected period of time that the installation would remain effective in addressing the operational and safety issues at the intersection. SIGNALIZED INTERSECTION MODERN ROUNDABOUT The design life for many highway projects is typically twenty years. However, the effective life of a traffic signal may be less if operational conditions at the intersection reach a point where additional major modifications to the intersection are needed. The volume-to-capacity (v/c ratio) represents the sufficiency of an intersection to accommodate the vehicular demand. A v/c ratio less than 0.85 generally indicates that adequate capacity is available and vehicles are not expected to experience significant queues and delays. As the v/c ratio approaches 1.0, traffic flow may become unstable, and delay and queuing conditions may occur. Once the demand exceeds the capacity (a v/c ratio greater than 1.0), traffic flow is unstable and excessive delay and queuing is expected. Under these conditions, vehicles may require more than one signal cycle to make it through the intersection. A review of the capacity analyses for the revised signalized intersection layout shows that v/c ratio for the northbound through and right lane and southbound travel lane The design life of a roundabout at this location would be longer than for a signal at this intersection because its capacity is higher. The FHWA’s Roundabouts: An Informational Guide shows that a single-lane urban roundabout (inscribed circle diameter 100- 130 feet) can process 20,000 vehicles per day. Assuming the 2002 daily traffic volume at the intersection (14,835 vehicles) and a 1.3% per year annual traffic growth rate (used by Marvin & Associates), the daily traffic volume at this intersection would not reach 20,000 vehicles until year 2026. Exhibit 4-6 in the FHWA’s publication suggests that a single lane roundabout can accommodate a circulating flow of 1,800 vehicles per hour. Considering this and the anticipated increase in traffic, the circulating flow would not exceed 1,800 vehicles per hour until year 2023. COMPARISON OF DESIGN OPTIONS -18- would be 0.86 and 0.91, respectively, in 2014. An additional capacity analysis run was made in an effort to determine when the v/c ratios on the north and south approaches may exceed 1.0, indicating the need for improvements. The analysis showed this would occur in 2019. Would the design option shift traffic? Would the option induce more traffic at the intersection? Traffic shifts (or cut-through traffic) refers to the number of vehicle trips that are diverted to other nearby lower volume streets as a result of conditions at the intersection. Associated effects of such traffic often include speeding, safety concerns, increased congestion, and general neighborhood disruption. “Induced travel” is a term that is frequently used to describe the observed increase in traffic volume that occurs soon after a new highway is opened or a previously congested highway is widened. Increased traffic on a highway can also result from operational improvements that reduce delays on the facility, such as improved signal timing or incident management. Induced travel is more frequently associated with major corridor expansion rather than the installation of “spot” improvements. SIGNALIZED INTERSECTION MODERN ROUNDABOUT A traffic signal would introduce delays to through traffic on Willson. This will be notable on Willson Avenue since northbound or southbound traffic was not previously required to stop. Traffic delays could deter some facility users to choose other alternate routes without signals. However, it is unlikely that a signal at the intersection would result in significant shifts in traffic to other nearby residential streets. Information from local residents suggests that the recently installed signal at Olive and Willson has resulted in some level of traffic shifts to side streets in the area, particularly South Tracy. This has posed a concern in the neighborhood due to travel speeds and more traffic in the vicinity of Longfellow School. Undoubtedly, some highway users would detour to side streets to avoid delays at the signal during peak travel times. However, adjacent streets are narrow with parking on one or both sides of the street, and less direct routes for north-south travel in the area. Using these adjacent streets would It is unlikely that the roundabout would significantly change traffic patterns. As indicated earlier, roundabouts typically result in less delay to approach traffic than traditional intersection treatments. Willson is an important arterial street in the community and represents one of the most direct routes for those commuting between residential areas on the southeastern portion of the city (and adjoining outlying county areas) and downtown Bozeman. Notable traffic shifts would be unlikely due to the narrow width, extent of on-street parking, and resulting travel speeds on adjacent streets. These conditions would make other nearby streets less desirable travel routes than Willson. COMPARISON OF DESIGN OPTIONS -19- not result in major savings in travel times over the use of Willson for many users. For this reason, substantial shifts in traffic from Willson to parallel side streets would not be expected. The City has also expressed a commitment to implement measures to prevent such traffic shifts to adjoining streets in the neighborhood. How does the project affect access to public transportation? The Bobcat Transit System provides transportation to students, faculty and staff of Montana State University Monday through Friday during fall and spring semesters. Non-MSU people may ride the bus if they pay the bus driver each time that they ride the bus. According to a recent schedule, the northeast corner of the intersection (Sigma Chi house) is a designated stop on the ASMSU Transit system. Route information indicates the corner is on the transit system’s Blue Commuter Route with stops for MSU bound passenger pickups at about 7:30 and 8:30 a.m. each day and home-bound stops at about 12:20, 4:30, and 5:30 p.m. daily. Route information indicates the MSU shuttle also leaves from the area once an hour from 9:10 to 11:10 a.m., 1:20 to 3:20 p.m. and 6:20 p.m. SIGNALIZED INTERSECTION MODERN ROUNDABOUT The availability of on-street parking along the east side of Willson north of College would be unchanged over present conditions. The parking lane (loading/unloading area) in front of the Sigma Chi house would continue to be available for stops by ASMSU transit vehicles. On-street parking would be eliminated for a distance of about 80-100 feet on each approach to the roundabout because the street would be “necked down” and splitter islands installed in these areas. This means on-street parking opportunities would be lost in front of the Sigma Chi fraternity house. Another stop location in the vicinity of the Sigma Chi house would have to be established. On-street parking opportunities would exist further north or south of College along the east side of Willson. How does the project affect short-term and long-term vehicular access in the area? Other than the effects already described, there are no other apparent short-or long-term effects on vehicular access to this area that would result from the installation of either a signal or roundabout at this location. What other operational effects are foreseeable? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Traffic lights can contribute to existing speeding problems as some drivers will speed up to make it through a traffic light or accelerate quickly after a green light. Roundabout controlled intersections can service traffic with decreased delay and greater efficiency than traffic signals, particularly at intersections where traffic COMPARISON OF DESIGN OPTIONS -20- The traffic signal would be equipped with Opticom emergency vehicle preemption. This system enables emergency service providers to manipulate the signal phases to facilitate passage through the intersection. volumes entering the roundabout are nearly balanced on all legs and where there are a high number of left turning vehicles. Traffic volumes on the approaches at the College- Willson intersection are not evenly balanced with the majority of the entering traffic being on Willson. High numbers of left turns are present only on the northbound approach leg of the intersection. The proposed roundabout has limitations on the size of vehicles that may pass through the intersection. The roundabout can only pass a large truck traveling north-south or east-west. Left turns can only be made by a 40-foot bus and single unit trucks. Emergency vehicles like fire trucks and ambulances could negotiate the intersection. However, large tractor-trailer trucks could not readily circulate through the intersection. The narrow width of College Street and existing curb radii likely already inhibits turning movements by large tractor-trailer vehicles. Since roundabout operation is continuous, it is not possible to coordinate the operation of roundabouts on an arterial route to provide smooth progression for arterial flows. This is not a major issue at this location because the nearest signals are located 6 blocks north (at Olive) and some 10 blocks south at Kagy Boulevard/South 3rd Avenue. Roundabouts impose a new form of traffic control that is not familiar to motorists in Bozeman. National experience suggests that drivers quickly learn how to drive in a roundabout. Since roundabouts are designed to keep traffic flowing without requiring vehicles to stop, there is no incentive for drivers to speed to make it through a changing light. COMPARISON OF DESIGN OPTIONS -21- How do construction and operating/maintenance costs compare? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The proposed signal would not require any new right-of-way acquisition. The preliminary cost estimate for construction of the proposed traffic signal as described above, mobilization, traffic control, contingencies, construction engineering, and inflation to the year 2005 for this location is approximately $180,000. This includes $18,000 for construction engineering. The preliminary cost estimate provided by the safety management section for construction of a traffic signal was $145,000. Maintenance costs of signalized intersections may total about $3,500 per year and typically include electricity, maintenance of detector loops, signal heads, controller, timing plans, illumination, and occasional sign replacement. The cost of electrical power for operating the signalized intersection 24 hours per day typically accounts for some $1,500 of the annual maintenance and operating cost. The proposed roundabout would require an estimated 2,435 square feet of new right-of- way. MDT does not have an estimate of the cost of acquiring the needed right-of-way. MDT has not prepared a detailed cost estimate for construction of the proposed roundabout. However, larger roundabouts can easily cost as much or more than a traffic signal installation. Even if the construction cost for a roundabout is higher than traffic signals, a life cycle economic analysis including construction, operation, maintenance and collision cost reduction of each type of control will usually show the roundabout has a higher benefit/cost ratio. Roundabouts do not require as much maintenance as signalized intersection and only require electricity for lighting at night. The initial and operating costs for lighting the roundabout may be higher than for the signalized intersection due to the need to provide additional lighting on each approach. Maintenance costs would also include landscape maintenance and occasional sign replacement. Are there any special maintenance issues are associated with either design option? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Signals are mechanical devices that not only require maintenance but also periodically malfunction. They are also dependent upon electrical power and do not, therefore, provide any traffic control during power failures. Snow removal in the roundabout may require adjustments to the plowing procedures used by the city. Snow plows should be able to negotiate the roundabout without difficulty but would be required to push show from the inside to the outside of the roundabout. National experience shows that roundabouts have been installed other locations (including Colorado, Wisconsin, Vermont and Ontario) where snow is common during the winter months. COMPARISON OF DESIGN OPTIONS -22- B. Effects to On-street Parking and Driveways Except in the immediate vicinity of the corners, on-street parking opportunities exist along both sides of Willson north and south of the College Street intersection. Observations suggest that on-street parking along Willson in front of the Story Mansion is infrequent at this time. There is parking on the north side of College east of Willson and a No Parking/Loading Zone on the south side of College east of Willson adjacent to the daycare facility. The narrow width of College Street west of the intersection (about 24 feet) does not provide sufficient space for on-street parking along the street. The existing number of on-street parking spaces available on each block face near the Willson and College intersection is provided below: 700 block Willson (west side) 10 spaces 700 block Willson (east side) 9 spaces 800 block Willson (west side) 12 spaces (in front of Story Mansion) 800 block Willson (east side) 11 spaces College (west approach) On-street parking not permitted College (east approach/north side) 5 spaces (to parking lot driveway) College (east approach/south side) Signed No Parking/Loading Zone Would on-street parking be lost? If so, how much? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The proposed design for the intersection involves shifting the lanes to the west and eliminating the left turn pocket for southbound Willson Avenue traffic. MDT has proposed reducing lane widths and shortening taper lengths for the left turn lane to help retain as many on-street parking spaces as practicable. Due to the westerly lane shift, on-street parking would be lost between the intersection and the existing driveway in front of 725 South Willson, resulting in the elimination of 3 spaces. On-street parking opportunities would be eliminated along most of the west side of Willson in front of the Story Mansion, resulting in a loss of 10 parking spaces. Space would remain for two vehicles to park on Willson in front of the Story Mansion immediately north of Harrison Street. For the most part, the availability of on- street parking along the east side of Willson north and south of College would be unchanged over present conditions. One on-street parking space in front of the On-street parking would be eliminated for a distance of about 80-100 feet on each approach to the roundabout. The parking restriction is necessary because the street would be “necked down” and splitter islands installed in these areas. Parking would not be allowed on the circulating roadway of the roundabout because parking maneuvers would prevent the facility from operating in a manner consistent with its design. Most notably, this means on-street parking opportunities would be lost in front of 725 South Willson (the residence at the northwest corner), in front of the Sigma Chi fraternity house, in front of the residence/daycare at 804 South Willson and the residence immediately to the south (810 South Willson), and in front of the Story Mansion property. The proposed roundabout design would eliminate on-street on Willson in front of the daycare facility. A loading/unloading zone and/or 3 space parking area for the daycare east of Willson along the south side of College Street could be provided if a portion of the existing boulevard was removed. COMPARISON OF DESIGN OPTIONS -23- daycare and one near the Sigma Chi house would likely be eliminated to ensure adequate sight distance at the intersection. Due to narrow width of College Street, the on-street parking situation would remain unchanged east and west of Willson. Parking would generally be restricted for a short distance back from the stop bars to provide adequate sight distance at the intersection. In total, 15 on-street parking spaces could be lost with the signalized intersection design. In total, 20 on-street parking spaces would be lost through the installation of a roundabout. If 3 spaces were replaced along the south side of College east of the intersection, the net loss of on-street parking would be 17 spaces. Along Willson between College and Alderson, three residential driveways exist along the west side of the street and one driveway exists along the east side of the street. Between College and Harrison, there are no driveways along the west side of Willson and two driveways along the east side of the street. East of Willson, driveways exist for the Sigma Chi parking lot and for a garage for the residence/daycare on the southeast corner of the intersection. Would residential driveways be impacted? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The proposed signalized intersection design would not eliminate any driveways. Driveway use in the vicinity of the intersection may be inhibited for a short periods when queues of vehicles stopped for the signal extend far enough behind the stop bars to block driveways. These conditions would not be expected to continuously occur throughout the day so driveway access would probably not be much different than at present during these off-peak periods. As discussed earlier, the capacity analyses for the proposed signalized intersection layout predicted maximum queue lengths on Willson south of the intersection to be 12 and 13 vehicles, respectively, under 2002 and 2014 peak hour traffic. Predicted maximum queue lengths on Willson north of the intersection were 14 and 19 vehicles, respectively, under 2002 and 2014 peak hour traffic. Two driveways accessing directly onto Willson (one north of the intersection on the west side and one south of the intersection on the east side) exist in areas where street narrowing would occur and where splitter islands for the roundabout would be installed. Driveway access at these locations would be perpetuated with the proposed roundabout design. However, the splitter islands would change accessibility to these driveways for residents by inhibiting left turns from Willson into these driveways. In areas where splitter islands exist, residents would be able to make right turns into the driveways and would be required to back out to the left into oncoming traffic. In the case of the driveways located nearest to the intersection, residents would be backing directly out into the travel lanes since there would be no parking lane in this area. Queue formation at the roundabout would not be expected to block driveways since traffic can continually move. The roundabout COMPARISON OF DESIGN OPTIONS -24- Assuming an average of 20 feet per vehicle (17 feet for the vehicle and 3 feet between vehicles), northbound traffic on Willson could extend 260 feet back (more than 3/4 block) from the stop bar location during the peak hour in 2014. Southbound traffic could extend 380 feet back (a full block and across Alderson Street) from the stop bar during the peak hour in 2014. Driveways accessing Willson in the blocks immediately north and south of the intersection would be periodically blocked during peak hour traffic. The calculated queue lengths (8-10 vehicles) on College Street west of the intersection means traffic could extend some 200 feet back from the stop bar – or beyond the alley between Willson and Grand. The signal would have little effect on the driveway accesses from College east of Willson. For residents backing out of their driveways, the proposed design should be as safe as the existing situation since a 10- foot wide buffer area (parking lane) would separate travel lanes from the curb. Because of the painted lane markings, residents could back out to the left or right if traffic conditions permitted. would also slow travel speeds on Willson making backing maneuvers from the affected driveways somewhat safer. C. Effects to Sidewalks and Pedestrian Crossings Sidewalks presently exist along both sides of each street. Curb bulb outs have been installed at all four corners to narrow the crossing distance and facilitate east-west pedestrian crossings of Willson at College Street. A pedestrian crosswalk on Willson has been designated on the north side of the intersection and is marked with pavement markings and appropriate advance crossing and crosswalk signing. Crosswalk markings do not exist for the pedestrian crossing location on Willson on the south side of the intersection. COMPARISON OF DESIGN OPTIONS -25- Typical view of streetscape in the project area. Pedestrian crossing at the intersection. How would the design option affect existing sidewalks and pedestrian crossings in the district? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The existing bulb-outs would be removed at all four corners and the curb radius on the west side of Willson at College would be modified to accommodate turns by school busses. New curb ramps would be constructed at the intersections to facilitate handicapped access. New driveway approach aprons would be constructed in the boulevard areas and the sidewalk through affected driveways would be replaced as necessary. Button-activated pedestrian signals (with Walk-Don’t Walk indicators) and crosswalks would be installed on all four legs of the intersection. Existing thermoplastic crosswalk makings would need to be removed and replaced with new pedestrian crossing signs and pavement crosswalk markings. The proposed roundabout configuration would require substantial modifications to the pedestrian facilities at this intersection. The existing bulb-outs and adjoining curbing would be removed at all four corners and areas of existing sidewalk on each corner would be removed. Existing thermoplastic crosswalk makings would need to be removed. When pedestrian crossings are provided for the approach roads at roundabouts, they are placed approximately one car length back from the entry point. For this reason, pedestrian crossing locations on College Street would be shifted about 40 feet further away from the intersection and crossing locations on Willson would be moved about 50 feet north and south of their respective existing locations. New sections of sidewalk would be added to each corner along with curb ramps and marked crosswalks that cross the streets approaching the roundabout. The splitter islands on each approach would serve as a refuge area for pedestrians. Signs for pedestrian crossings would need to be revised. COMPARISON OF DESIGN OPTIONS -26- D. Effects on Traffic Safety What is the dominant crash trend at the existing intersection? Based on the accident analyses done for this project, the trend is broadside crashes from College Street traffic being struck while attempting to cross over or onto Willson Avenue. With this intersection meeting 4 of 8 traffic signal warrants, it is clear that high volumes and lack of acceptable gaps to provide for the orderly movement of traffic from College Street to Willson Avenue is the root of the crash pattern. Will the design option address the accident trend at this location? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Traffic signals play an important role in making intersections safer. Research has shown that, under the right circumstances, the installation of traffic signals will reduce the number and severity of crashes. The installation of a traffic signal would correct the broadside collision pattern by allocating time for traffic movements from the minor street (College) onto Willson and for northbound left turning traffic. The roundabout configuration would be an effective way to address the identified crash pattern at the College-Willson intersection. Since vehicles all travel around the center island in the same direction, head-on and left-hand turn (T-bone) collisions are eliminated. The angles of traffic interaction and slower speed through the roundabout would help reduce the severity of accidents. The safety improvements associated with roundabouts are the result of speed reduction through the intersection and the fewer conflict points for drivers and pedestrians. The figures below illustrate typical conflict points for traditional and roundabout intersections. Is there potential for the type of crashes typically occurring at the intersection to change? SIGNALIZED INTERSECTION MODERN ROUNDABOUT While traffic signals may reduce the number of angle collisions at an intersection, it has been well documented that signals can also cause an increase in other types of A Kansas State University research team has concluded that the modern roundabout is the safest and most efficient form of intersection control available today. COMPARISON OF DESIGN OPTIONS -27- accidents (notably rear-end collisions). Rear-end collisions often increase after a signal is installed; however, such collisions are usually less severe than broadside collisions. In a recent Insurance Institute for Highway Safety (IIHS) study of 24 intersections in the U.S. where stop control and traffic signals were replaced with modern roundabouts, there was a 39% overall crash reduction, a 76% injury crash reduction and a 90% fatal crash reduction. These intersections were a mix of urban, suburban and rural environments. The study concluded, “results are consistent with numerous international studies and suggests that roundabout installation should be strongly promoted as an effective safety treatment for intersections.” (Crash Reduction Following Installation of Roundabouts in the U.S., Insurance Institute for Highway Safety, Arlington, VA March 2000). The FHWA’s publication, Roundabouts: An Informational Guide, reports that “experience in the U.S. shows a reduction in crashes after building a roundabout of about 37% for all crashes and 51% for injury crashes.” Further, the publication states that “If only small to moderate single-lane roundabouts are considered, the reductions are 73% for injury crashes. Mean reductions in crashes after converting to a modern roundabout from other traffic control devices have been similar in other countries: Australia 41-61% for all crashes and 45- 87% for injury crashes; Germany 36% all crashes; United Kingdom 25-39% injury crashes.” E. Effects on Pedestrian and Bicyclist Safety Existing pedestrian facilities at the intersection were discussed earlier. Marvin & Associates counted pedestrian crossings at the intersection during their data collection efforts in 2002. The firm noted pedestrian volumes were highest during the evening peak hour and documented a total of 68 pedestrian crossings at the intersection during their evening peak hour counts. The accident analyses done for the 1999 through 2002 period at this intersection (since 1999) shows one accident involving a pedestrian crossing Willson. As indicated previously, bicyclists on South Willson Avenue and College Street must share the road with motorized vehicles as there are no separated bike paths or designated bicycle lanes along either street. The study by Marvin & Associates did not count bicycle traffic at this intersection. COMPARISON OF DESIGN OPTIONS -28- What effect would the design option have on safety for non- motorists? SIGNALIZED INTERSECTION MODERN ROUNDABOUT While the lengths of the crosswalks on Willson would be slightly longer due to the removal of pedestrian bulb-outs, the intersection would be equipped with button- activated pedestrian signals (with Walk- Don’t Walk indicators) and crosswalk markings would be installed across all four legs of the intersection. Designated crosswalks on all four legs of the intersection and pedestrian signals identifying safe times for crossing the streets would enhance safety for pedestrians over present conditions. There is a potential for vehicle/pedestrian conflicts whenever motorists speed up to avoid stopping at the signal, run red lights, and make right turns on red. Pedestrians may also become impatient and not wait for the pedestrian crossing signal. Some pedestrians don’t bother to use pedestrian buttons, preferring to attempt crossing traffic lanes at the first apparent opportunity. Installing a traffic signal would not change the way bicycle use is presently accommodated on either street. A Dutch study of 181 intersections converted to roundabouts reported a 73% reduction in all pedestrian crashes and an 89% reduction in pedestrian injury crashes (FHWA-RD-00- 067). Literature reviews indicate that roundabouts are safer for pedestrians than signalized intersections because: • There are fewer conflict points for vehicles and pedestrians. • The design and geometry of the roundabout forces vehicles to approach and travel through the roundabout intersection more slowly. • Roundabouts force drivers to pay attention to their surroundings as they approach and pass through the intersection. • Roundabouts present frequent opportunities for pedestrians to cross safely during gaps in slow-moving traffic. • The crossing distance is shorter, and safe gaps are easier to judge in slow- moving traffic. Pedestrians only have to cross one lane at a time. • Splitter islands" provide a refuge storage area for pedestrians. Concerns have been raised about the ability of blind pedestrians to safely negotiate roundabouts without protective signals that stop traffic. These concerns exist due to the “non traditional” geometry of the roundabout and the shift of crosswalks away from the corner and longer associated travel distance. Properly designed roundabouts also safely accommodate bicycles. Because vehicles are traveling at speeds comparable to bicycle speeds, bicyclists can negotiate the roundabout like motorized vehicles by using traffic lanes or they may traverse the intersection by using pedestrian facilities. COMPARISON OF DESIGN OPTIONS -29- F. Environmental Effects 1. RIGHT-OF-WAY AND UTILITIES The existing right-of-way for Willson Avenue is 80 feet wide and 60-feet wide for College Street. Utility poles and overhead electrical lines are located along the north side of College Street and cross Willson Avenue just north of the intersection. Existing street lighting is located in the boulevards along the street. Would the design option require the acquisition of new right-of-way? SIGNALIZED INTERSECTION MODERN ROUNDABOUT No additional right-of-way would be needed for the signalized intersection improvements. Roundabouts typically require more space for the circular roadway and central island than the rectangular space within traditional four-way intersections. Consequently, roundabouts can have a more significant right-of-way impact on corner properties at the intersection. The proposed roundabout configuration would require about 800 square feet of new right-of-way from the northwest corner of the existing intersection and about 545 square feet of new right-of-way from the other corners of the intersection. In total, about 2,435 square feet of new right-of-way would be needed. New right-of-way would be needed from residential properties at 725 South Willson and 804 South Willson, the Sigma Chi Fraternity, and from the City-owned Story Mansion property. Would the design option require the relocation of any housing and commercial, industrial, non-profit businesses? No relocations would be required for either design option. Would the design option impact existing utilities or require notable modifications to utilities? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Electrical service for the new signal would be available from a power pole northeast of the intersection. New signal poles at the intersection would need to be located to avoid overhead power lines. The FHWA’s Roundabout Information Guide identifies the importance of illumination at roundabouts so drivers can see the change in roadway layout and make the appropriate traffic maneuvers. Therefore, it is likely that COMPARISON OF DESIGN OPTIONS -30- A historic concrete lamp post on the northeast corner of the intersection would probably need to be removed and reset at a nearby location. additional lighting to supplement the existing decorative lights would be needed at a roundabout at Willson and College. Guidance suggests that all approaches should be illuminated and that it is necessary to improve the visibility of pedestrians and bicyclists. Electrical service would have to be extended to supplemental lighting devices. Existing lamp posts would need to be removed from the northeast and southwest corners of the existing intersection and reset to accommodate the development of a roundabout. 2. LAND USE EFFECTS The intersection is situated in the south central part of the City in a residential neighborhood. The blocks immediately north of the intersection consist almost entirely of single-family homes. However, the Sigma Chi fraternity house, considered a multi-family residential use in the Bozeman 2020 Community Plan, exists on the northeast corner of the intersection. The Children’s Development Center is operated from a residence located at the southeast corner of the intersection. The Story Mansion, formerly used as the SAE fraternity house, is located on the block immediately southwest of the intersection. The historic Story Mansion, acquired by the City of Bozeman in 2003, is currently undergoing exterior renovations. Properties adjoining the Willson Avenue-College Street intersection are zoned either R-1 or R-2 according to the City’s Zoning Map meaning the principal land uses permitted in the zones are residential. In general, offices and commercial uses are prohibited. The project area is also located within a designated Neighborhood Conservation Overlay District. Is the project consistent with local land use plans and zoning? The Bozeman 2020 Community Plan contains several goals, objectives, and policies that are relevant to the proposed project. These are paraphrased below: • retain and enhance Bozeman’s unique identity, characterized by its natural surroundings, its historic and cultural resources, and … • ensure adequate levels of public services and infrastructure to support the City’s growing population in a cost-effective manner. • achieve an orderly pattern of development that enhances the fabric of the community and preserves safety and quality of life. • create pedestrian-oriented neighborhoods and foster alternate modes of transportation. The Bozeman 2020 Community Plan also describes an overall community desire to shift towards a development pattern promoting a City where residents have balanced COMPARISON OF DESIGN OPTIONS -31- transportation options such as walking, biking, mass transit, or driving with neighborhoods being centers of social activity and interaction. The City’s Neighborhood Conservation Overlay District designation is also used to protect and enhance neighborhoods or areas of significant land planning or architectural character, historic landmarks or other built or natural features for the educational, cultural, economic benefit or enjoyment of Bozeman citizens. Relevant policies of the Conservation Overlay District as identified in the Bozeman 2020 Community Plan follow: • Protect, preserve, enhance, and regulate structures, archaeological sites, and areas that are reminders of past eras, events, or persons important in local, state, or national history; or which provide significant examples of land planning or architectural styles or are landmarks in the history of land planning and architecture; or which are unique or irreplaceable assets to the City and its neighborhoods; or which provide examples of physical surroundings in which past generations lived; or which represent and express the unique characteristics of small agricultural-based, Western city developmental patterns. • Develop and maintain an appropriate environment for buildings, structures, sites, and areas that reflect varied planning and architectural styles and distinguished phases of Bozeman’s history and prehistory. • Stimulate and enhance human life by developing educational and cultural dimensions that foster the knowledge of Bozeman’s heritage and cultivate civic pride in the accomplishments of the past. • Seek to maintain and enhance the many private and public elements that are unique to the fabric, theme, and character of each neighborhood and area, including lighting, pathways, street trees, natural features, and other identified features. SIGNALIZED INTERSECTION MODERN ROUNDABOUT Installing a traffic signal at the intersection would not appear to be in conflict with the goals, objectives and policies of the City’s land use plans and zoning regulations. The proposed intersection improvements were developed as part of a community- based transportation planning effort and are included in the Greater Bozeman Area Transportation Plan 2001 Update, adopted by the Bozeman Transportation Coordinating Committee (TCC) in 2001. Installing a roundabout at the College and Willson would not conflict with the goals, objectives and policies of the local land use plans or zoning. Due to the traffic calming effects that can potentially be achieved with a roundabout, this design offers advantages over a signal in terms of the community’s apparent desire to shift towards the provision of balanced transportation options and neighborhood enhancement. A roundabout offers the opportunity to add a unique design element to the South Willson neighborhood. Would the design option induce changes in land use and density? If so, what changes might be expected? Overall, the land use effects of the project are considered minor and beneficial to the general community since the improvements are safety-oriented and occurring within the context of a recognized and accepted plan for community transportation improvements. COMPARISON OF DESIGN OPTIONS -32- Installing a traffic signal or roundabout at this intersection would not be expected to induce changes in land use or density in this neighborhood. The Bozeman 2020 Community Plan, adopted by the City Commission in October 2001, provides overall guidance on land use planning within the City of Bozeman and immediately adjacent lands around the City. The Plan does not anticipate any major changes in land use patterns in the vicinity of the Willson Avenue-College Street intersection. The future use of the Story Mansion is unknown at this time, although proposals ranging from residential and commercial uses to a community center have been discussed for the property. Property in the vicinity of the intersection is zoned for residential uses (either R-1 or R-2) according to the City’s Zoning Map. Because the project area is in a Neighborhood Conservation Overlay District, deviations from underlying zoning requirements may be granted by the City Commission after considering the recommendations of the Design Review Board or Administrative Design Review staff. Subsection 18.28.070 of the City’s Unified Development Ordinance outlines the criteria for granting deviations from the underlying zoning requirements. The criteria for approving such deviations are listed below: • Modifications shall be historically appropriate for the building and site in question and the adjacent properties: • Modifications will have minimal adverse effect on abutting properties or the permitted uses; and • Modifications shall assure the protection of the public health, safety and general welfare. Changes to existing land uses in the area would occur only if a property owner(s) proposes such a change and the City allows a deviation from permitted uses under the procedures outlined in its Unified Development Ordinance. The City would hold a public hearing prior approving such land use changes. Considering these applicable City regulations and the public and private interests focused on preservation of Bozeman’s historic residential areas, it would seem that adequate “safeguards” are in place to prevent undesirable land use changes from occurring in this neighborhood. Would the design option induce growth? The City of Bozeman has experienced substantial increases in population and associated land area since the late 1980’s and has been one of the fastest growing communities in Montana over the past two decades. There is nothing to suggest this trend will not continue over the foreseeable future as Bozeman’s increasing importance as a regional economic, educational, and cultural center. This growth has resulted in many land use changes and the need for transportation system improvements within the community. The connection between transportation and land use is well recognized in planning literature. Land development generates travel, and travel generates the need for new facilities, which in turn increases accessibility and attracts further development. Simply put, everything that happens to land use has transportation implications and every transportation action has some effects on land use. However, many other factors also influence land use. These include overall population and economic growth, individual preferences and life style choices, availability of necessary infrastructure, changing technology, local planning and zoning polices, and geographic and topographic conditions. COMPARISON OF DESIGN OPTIONS -33- Projects increasing the ability of the transportation system to handle traffic volumes (like the addition of travel lanes or new system links) or creating new access points from an existing road (new intersections or interchanges) have the greatest potential to cause land development changes. Projects designed to enhance traffic operations and safety (like signalization, traffic control, channelization, median treatments, turn pockets/lanes, and other benefits to traffic flow) usually have minor or insignificant potential to cause land use changes because they do not change the development potential of adjoining land. Adding a traffic signal or roundabout at the College-Willson intersection is an improvement intended to enhance safety and operations at one location on the City’s street system. Due to the limited and localized nature of the project, adding a signal or roundabout would be unlikely to cause any notable land use changes or affect development patterns in the area. Are there residents with special needs (disabled, minority, elderly residents) in the area? The most obvious special needs group within the area is a daycare for young children. The Children’s Development Center, a daycare/preschool facility, is located in a residence on the southeast corner of the intersection of College Street and South Willson Avenue. Currently, there is parking on the north side of College east of Willson and a No Parking/Loading Zone on the south side of College east of Willson. Space for about three parked cars exists along the east side of Willson in front of the daycare. SIGNALIZED INTERSECTION MODERN ROUNDABOUT This option would result in a loss of on- street parking for the daycare facility. MDT’s preliminary design layout shows one parking space would exist on Willson in front of the daycare facility and no parking spaces adjacent to the facility along College Street. The proposed roundabout design would eliminate on-street parking on Willson and College at the daycare facility. With modifications to the existing boulevard, a loading/unloading zone and parking area for the daycare could be provided east of Willson along the south side of College. Does the project area contain emergency service facilities such as fire stations, police facilities, hospitals/medical facilities; or community services such as schools, libraries, or post offices? No emergency or community service facilities exist in the vicinity of the intersection. Although unknown at this time, it is possible the Story Mansion may be used as a community center in the future. Are response times for the emergency services or access for the community services significantly affected by the project? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Response times for emergency vehicles would not be significantly changed. Traffic signals are typically equipped with remote override equipment so emergency services vehicles can turn the light green in the direction they’re traveling. Response times would not be significantly affected with a roundabout. A roundabout is typically designed to safely operate at speeds between 15 and 25 mph. At most, the time lost by emergency vehicles negotiating the roundabout would only be a few seconds. COMPARISON OF DESIGN OPTIONS -34- Modern roundabouts are typically designed to accommodate emergency and large-sized vehicles. Most common types of emergency vehicles should be able to readily pass through the new intersection layout. 3. TRAFFIC NOISE Is the project a Type I project requiring a detailed noise study? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The signalized intersection layout would not be a Type I project because since it would not significantly change the horizontal or vertical alignments of the streets or increase the number of through lanes at the intersection. A roundabout would be a Type I project because horizontal alignment of intersecting streets would be substantially changed. The FHWA noise regulations and MDT’s Noise Policy requires noise analyses for all Type I projects. Are there schools, health facilities, or other sensitive receptors in the project area? Residences in the vicinity of the intersection comprise the most sensitive noise receptors in the project area. Would traffic noise or vibration be expected to increase? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Overall, noise levels at the intersection would not be expected to be much different than currently exists. However, residents living near the intersection may experience changes in traffic noise due to vehicles stopping and starting resulting in increased tire and engine noise. The AASHTO Green Book notes that “noise produced by automobiles increases dramatically with speed.” Because the design would reduce speed of vehicles traveling along the Willson Avenue corridor, it can be assumed that there would be less noise generated by fast moving vehicles. The number of vehicles accelerating from a stop on College Street would be reduced, but there would be offsetting noise from vehicles accelerating as they exit the roundabout. The circular roadway for the roundabout would be closer to residences on three corners of the intersection than with the existing four-way intersection suggesting noise could increase for these locations. However, it is likely that any increase in traffic noise due to the proximity of the new travel lane at the corners would be offset by decreased vehicle travel speeds. COMPARISON OF DESIGN OPTIONS -35- 4. AIR QUALITY IMPACTS Is the project in an area where Federal Clean Air Act conformity requirements apply? Under the Clean Air Act of 1970, EPA developed primary and secondary National Ambient Air Quality Standards (NAAQS) for each of the seven criteria pollutants: carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, fine particulate matter, and sulfur dioxide. These criteria air pollutants were selected by EPA based on extensive scientific research showing the direct relationship between exposure to pollutants and their short- and long- term effects on human health and the environment. Montana has adopted additional state air quality standards. The state has also established Montana Ambient Air Quality Standards (MAAQS) for these same air pollutants. Carbon monoxide, hydrocarbons, nitrogen oxides, and particulate matter are the most notable emissions associated with vehicles and their use of the road system. The air quality is Bozeman is generally good – there are no areas within the City designated as non-attainment areas for any vehicle-related pollutants (most notably particulates or carbon monoxide). Federal and state air quality standards for the seven criteria pollutants have not been exceeded in the City of Bozeman. However, according to the Bozeman 2020 Community Plan, the City is classified as a high risk area for non-attainment for small particles and carbon monoxide. Are any other project-level conformity issues present? The intersection is located in an “unclassifiable/attainment” area of Montana for air quality under 40 CFR 81.327, as amended. As such, this proposed project is not covered under the EPA’s Final Rule of September 15, 1997 on Air Quality Conformity. What air quality effects are typically associated with the design option? Although motorized vehicles are classified as a “mobile source” of pollutant emissions, intersections act as a point location or “source” of pollutant emissions because internal combustion engines operate less cleanly when decelerating, idling or accelerating than at steady speeds. Obviously, there is some low level of emissions generated at the intersection due to vehicle movements and idling on the stop-controlled legs on College Street. However, there is nothing to suggest that a “hot spot” carbon monoxide analysis or a particulates (PM-10) analysis is warranted at this intersection. SIGNALIZED INTERSECTION MODERN ROUNDABOUT Signalized intersections force motorized vehicles to do more decelerating, idling and accelerating than do roundabouts. A traffic signal would require that vehicles on each leg of the intersection stop for varying amounts of time corresponding to the signal phases. With a signal, traffic on Willson would periodically stop as required to permit traffic movements from College Street. Currently, traffic on Willson stops Roundabouts reduce vehicular emissions by making traffic flow orderly and reducing the need for vehicles to stop at the intersection. Mandavilli, Russell, and Rys examined the impact of modern roundabouts on vehicular emissions and published a paper on this topic in 2003. Their research included an extensive literature review and an examination of five sites in Kansas and one COMPARISON OF DESIGN OPTIONS -36- only for left turning vehicles or to permit pedestrian crossings. Emissions from vehicles stopped at traffic signals (or stop signs) are greater than from moving vehicles. Therefore, the amount of delay, length of queues, and proportion of vehicles stopped at the intersection are all factors in the level of vehicular emissions. site in Nevada where modern roundabouts were installed at intersections where varying degrees of stop controls formerly existed. The authors concluded that significant decreases in the carbon monoxide, carbon dioxide, nitrogen oxides, and hydrocarbons resulted after the installation of roundabouts. The reduction in delays, queues, and proportion of vehicles stopped at the intersections studied suggest that the enhanced operational characteristics account for the reduction in vehicular emissions. The FHWA’s Roundabouts: An Informational Guide states: “Roundabouts may provide environmental benefits if they reduce vehicle delay and the number and duration of stops compared with an alternative. Even when there are heavy volumes, vehicles continue to advance slowly in moving queues rather than coming to a complete stop. This may reduce noise and air quality impacts and fuel consumption significantly by reducing the number of acceleration/deceleration cycles and the time spent idling. In general, traffic through roundabouts generates less pollution and consumes less fuel than traffic at fixed-time signalized intersections.” 5. VISUAL IMPACTS/AESTHETICS Has aesthetics surfaced as a community or neighborhood concern? YES. The aesthetics of the proposed improvements at the College-Willson intersection are one of several concerns expressed by neighborhood residents, local historic preservation interests, and others. What types of project features are proposed? SIGNALIZED INTERSECTION MODERN ROUNDABOUT This design option includes the installation of four metal support poles, mast-arms, and signal heads, both over travel lanes and on mast arm support poles. In addition, a pedestal-mounted traffic controller would be installed on the southwest corner of the intersection. Willson Avenue would be marked to add a This option would install a 100-foot inscribed diameter roundabout with a raised center island. The roundabout would include raised concrete splitter islands at all four approaches, additional lighting and regulatory/guidance signing on each approach. New pedestrian crossing locations would be established at the intersection. COMPARISON OF DESIGN OPTIONS -37- left-turn lane for northbound traffic. Pedestrian crossings with pedestrian signals would be provided. Minor work would be done on sidewalks and driveway areas. Please refer to FIGURE 1 (on page 9) showing the proposed layout of the signalized intersection. Please refer to FIGURE 2 (on page 11) showing the proposed roundabout at this location. What noticeable changes in the physical characteristics of the existing environment would be caused by the design option? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The existing four-way street configuration with boulevards would be perpetuated. However, the support poles, mast-arms, traffic signal heads, pedestal-mounted controller required for the signal, and necessary signing would be new features at this intersection. The existing bulb-outs on Willson at the intersection would be removed and more standard curb radii installed. Minor tree trimming would also be necessary at the intersection to allow for the installation of signal support poles and mast arms and to ensure the signals are visible on each approach. The construction of the roundabout would result in a substantial change in the appearance of this part of the South Willson neighborhood. The roundabout would be an entirely new form of intersection treatment in a neighborhood which was developed following a grid pattern. The circular configuration of the roundabout would require alterations to existing boulevards and the removal of existing sidewalks and curb and the construction of new sidewalk and curb that would conform to the new circular roadway design. Most significantly, between 9 and 12 mature street trees would need to be removed in the vicinity of the intersection. Other notable physical changes associated with the roundabout includes: the likely addition of supplemental street lighting and more signage to increase the visibility and recognition of this new street layout; the installation of raised center island and raised concrete splitter islands on each approach; and the relocation of several historic lamp posts along Willson. Will the design option complement or contrast with the visual character desired by the community? SIGNALIZED INTERSECTION MODERN ROUNDABOUT One of the most frequently heard comments from residents of the neighborhood opposed to the installation of the traffic signal is that the signal would be Based on public input received to date, it appears that residents of the South Willson neighborhood feel that a roundabout is a more suitable treatment for this intersection COMPARISON OF DESIGN OPTIONS -38- “out of character” with this historic neighborhood. It is assumed that this comment relates in part to the changes in visual character associated with the signal installation and resulting traffic operations. These changes are discussed in this section. than a traffic signal. Apparently, one of the reasons for their support is that the feature would have more visual appeal than a traffic signal. Will the project changes likely be mitigated by normal means such as landscaping and architectural enhancement or will avoidance measures be necessary to minimize adverse change? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The support poles, mast-arms, and traffic signal heads would introduce materials that are not historic to the district. It is the intent of the MDT, however, to use signal poles, mast arms, and other associated hardware that are black and powder-coated to help blend them into the neighborhood. Roundabouts can be very appealing as architectural features within the streetscape. The center island offers a good opportunity to introduce simple plantings or other elements that can enhance or reflect the individual character of this neighborhood. Cooperation between MDT, the City, historic preservation officials, and with neighborhood residents would be needed to develop an acceptable design for the roundabout. Will this design option, when seen collectively with other projects, result in an aggregate adverse change in overall visual quality or character? SIGNALIZED INTERSECTION MODERN ROUNDABOUT A traffic signal would introduce new signal poles, equipment, and associated hardware to the intersection. It is also recognized that the signal would be installed in an entirely residential neighborhood. However, such traffic control devices are not uncommon in Bozeman and would not be the first in this portion of the community since other signals exist at the Olive and Willson and Kagy/South Third/Willson intersections. The overall changes to the visual character of the intersection would be substantially less adverse than with the roundabout option because the street configuration (curb lines, boulevards, and sidewalks) would remain relatively unchanged and street trees would not have to be removed. The physical impacts (change in street configuration, removal of street trees, addition of lighting and signing) associated with the roundabout would be a significant change in the neighborhood’s appearance in the vicinity of the intersection. The loss of mature trees from boulevards and the addition of modern street features would be the most adverse change in visual quality or character at the intersection. The roundabout could beneficially affect visual quality by adding landscaping and other elements to the streetscape. While such elements could help enhance the identity of the neighborhood, they would be new additions to the visual character of the area. COMPARISON OF DESIGN OPTIONS -39- How sensitive are potential viewer-groups likely to be regarding visible changes resulting from the design option? (Consider among other factors the number of viewers within the group, probable viewer expectations, activities, viewing duration, and orientation.) Residents living near the intersection would be the viewer group most sensitive to the visual changes associated with each design option. The viewer group least sensitive to the visual changes would be first time visitors to the historic neighborhood. Commuters using the Willson Avenue or College Street corridors would be expected to readily recognize changed conditions at the intersection but may they may also become “de-sensitized” to such changes due to their frequent travel through the area. SIGNALIZED INTERSECTION MODERN ROUNDABOUT Because traffic signals would be situated well above street level, lights from the signal heads would be visible from the upper stories of residences near the corner if there is an unobstructed view of the intersection. Residents on the corners of the intersection would be acutely aware of visual changes caused by the removal of street trees, changes in boulevards and sidewalks, and circular roadway configuration. What is the potential that the proposal may be controversial within the community, or opposed by any organized group? SIGNALIZED INTERSECTION MODERN ROUNDABOUT Neighborhood residents and other groups have been vocal about this project and expressed their opposition to the signal installation. Comments have been received from the Bozeman Historic Preservation Advisory Board, the Bozeman Pedestrian and Traffic Safety Advisory Board, a group identified as the “South Willson Improvement Association” and numerous residents of the neighborhood. Additionally, opinions about the project from B. Derek Strahn (a local historic preservation consultant) have been published in the At Home magazine distributed by the Bozeman Chronicle. Currently, the roundabout option would appear to be a less controversial design proposal than the signal. 6. SOCIAL IMPACTS/ENVIRONMENTAL JUSTICE Will the proposed project affect interaction among persons and groups or cause a change in social values? Neither design option would be expected to substantially affect the interaction between persons or groups in the area or cause a change in the social values. COMPARISON OF DESIGN OPTIONS -40- Roundabouts are a recognized traffic calming measure. Literature on traffic calming identifies increased neighborhood interaction, improved conditions for non-motorized facility users, and the creation of more livable communities as potential social benefits. Will community landmarks or social gathering places be affected by the project? The effects of each design option on the Story Mansion and associated property and on the Sigma Chi Fraternity House are described in Part IV of this document. Will the design option cause a redistribution of the population or an influx or loss of population? Neither design option would cause any changes in the population of the neighborhood or the community. Will certain people be separated or set apart from others? Neither the traffic signal nor roundabout designs would separate or isolate any segment of the population from others. What is the perceived impact on quality of life? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The prevailing sentiment among those opposing this project is that a traffic signal would adversely affect the quality of life by taking away from the residential nature of this historic neighborhood. A traffic signal is perceived as being more appropriate in “urban” settings. While safety and operational concerns at the intersection are generally acknowledged, there is disagreement whether a signal is the most appropriate way to address identified concerns. Many opponents of the traffic signal have advocated other alternatives: larger stop signs and stop ahead signs; a flashing yellow light; restricting parking on all legs of the intersection to improve sight distance; and beautifying the intersection without putting in a signal. The concern about eroding the quality of life due to increasing traffic in the City’s historic neighborhoods appears to be a community issue as much as a project- specific issue. The degree to which neighborhood residents believe a roundabout would affect their quality of life is unknown. Given the traffic calming benefits possible and a local desire to investigate this design option, it is assumed a roundabout would be perceived as having less impact on the quality of life than a traffic signal. It is unknown if public opinions would change once all the potential effects of installing a roundabout at this location are considered. COMPARISON OF DESIGN OPTIONS -41- Does the project area contain higher than average concentrations of traditionally under-served groups when compared to the area surrounding the project area or the city or county as a whole? The project area does not contain higher than average concentrations of underserved groups. Will the project result in disproportional effects to minority or low- income populations? The proposed project would be in accordance with Executive Order No. 12898, and would not create disproportionately high and adverse human health or environmental effects on minority and/or low-income populations. The proposed project would also comply with the provisions of Title VI of the Civil Rights Act of 1964 (42 U.S.C. 2000d, as amended) under the FHWA’s regulations (23 CFR 200). Are the benefits associated with the project equitable for all segments of society? The safety and operational improvements associated with both design options would primarily benefit the motoring public. 7. ECONOMIC IMPACTS Will the proposed action encourage businesses to move to the area? This area is zoned R-1 (Residential Single-household, Low Density) and R-2 (Residential Two-household, Medium Density) according to the City’s Unified Development Ordinance (UDO). Chapter 18.16.010 of the UDO says that the intent of these zoning districts is to provide residential development “within the City at urban densities, and to provide for such community facilities and services as will serve the area’s residents while respecting the residential character and quality of the area.” The only commercial uses authorized (as either accessory or conditional uses) under these zoning classifications are bed and breakfast operations, home-based businesses (subject to certain thresholds), and daycare centers. Offices and retail businesses are not permitted in either R-1 or R-2 zones. A land use shift away from residential uses in this neighborhood seems unlikely. Requests for deviations from authorized uses would have to be initiated by individual property owners according to the procedures outlined in the City’s UDO. The area’s designation as a Neighborhood Conservation Overlay District and the intense interest of residents in preserving the historic integrity of the area would also help prevent the area from an unwanted transition from residential to commercial uses. For these reasons, installing a traffic signal or roundabout at this intersection would not be expected to encourage new businesses to locate into this neighborhood. Would the design option affect property values in the neighborhood? Economic impacts (both positive and negative) can result from transportation projects that change the accessibility of an area or that cause a notable change the local environment. Property values, a measure of the desirability of a property considering its aesthetic COMPARISON OF DESIGN OPTIONS -42- qualities, accessibility, safety, and other factors, can be either positive or negative affected by transportation improvement projects. For example, a project creating new or substantially improving access to a developing commercial area could positively increase property values. Alternately, a project may increase noise, vibration, and air pollution or adversely affect the aesthetics of a neighborhood, making the area less desirable and reducing property values. A number of economic studies that examine how external factors affect housing prices and several examined affects that are relevant to transportation projects. Hughes and Sirmans (1992, 1993) looked at the effects of different traffic levels on the selling price of nearly 300 single family residences within the Baton Rouge, Lousiana metropolitan area. Their study tested the assumption that all else being equal, houses on high-traffic streets would sell for less than houses on low-traffic streets. High-traffic streets included those for which traffic counts were routinely done and that provide direct access to employment and shopping nodes or serve as feeder streets. Low-traffic streets provide access to only one street. The study concluded that a negative price effects were realized for residential properties close to high traffic streets. Hughes, Jr. W. T. and C. F. Sirmans (1992), “Traffic Externalities and Single- Family House Prices,” Journal of Regional Science, 61: 533-538. Hughes, Jr. W. T. and C. F. Sirmans (1993), “Adjusting House Prices for Intra-Neighborhood Traffic Differences,” The Appraisal Journal, 61: 533-538. A study by Li and Brown (1980) examined some 800 sales of single-family houses in 15 suburban towns located in the southeast sector of Boston considered the effects of a variety of external factors (air pollution, visual quality, noise and proximity to the ocean, rivers, recreational areas, schools, expressway interchanges, industry and commercial establishments) on property values. The study concluded that while air pollution did not have a significant effect on property values, visual quality has a positive impact and noise has a negative impact on property values in the sales they examined. Li, M. M. and H. J. Brown (1980), “Micro-Neighborhood Externalities and Hedonic Housing Prices,” Land Economics, 56: 125-141. Other studies have documented the beneficial effects of amenities like greenbelts, scenic views and improved access to transit facilities on property values. Negative effects on property values have been documented in studies examining residential proximity to power lines, noxious facilities and toxic waste sites, and the establishment of group homes for the mentally in neighborhoods. Literature reviews did not identify any economic studies focused specifically on the property value effects associated with the installation of either a traffic signal or roundabout. However, studies do suggest traffic calming measures (which include roundabouts) can help increase property values. As indicated previously, Hughes and Sirmans found that residential properties have higher values if located on a street with lower traffic volumes and speeds. A study by Bagby (1980) compared property values in a Grand Rapids, Michigan residential neighborhood after a traffic management program was implemented found that traffic volume reductions increased adjacent residential property values by 5- 25%. William Hughes and C.F. Sirmans, “Traffic Externalities and Single-Family House Prices,” Journal of Regional Science, Vol. 32, No. 4, 1992, pp. 487-500. Gordon Bagby, “Effects of Traffic Flow on Residential Property Values,” Journal of the American Planning Association, Vol. 46, No. 1, January 1980, pp. 88-94. COMPARISON OF DESIGN OPTIONS -43- Would the design option remove any property from the tax base or cause any changes in business activity? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The signalized intersection option would not remove any property from tax rolls or result in a change in business activity. The roundabout would require the acquisition of additional right-of-way from residential properties on three corners of the intersection. This would result in a minor reduction in the amount of taxable property to the local government. Although new right- of-way would be needed from the Story Mansion property, there would be no loss of taxable property since the City owns the property. The roundabout would not result in a change in business activity in the area. Can it be anticipated that the project will create or eliminate jobs in the local area? Installing a traffic signal or roundabout at this intersection would not create or eliminate any jobs in the area. Constructing the improvements would create a minor amount of work for temporary laborers, technicians, and suppliers of necessary construction materials and components. Will the project have economic impacts outside the immediate area? Other than the economic benefits possible through a reduction in motor vehicle accidents that could be experienced by all street users, there few economic effects that would occur beyond the project area. The cost of electricity to operate the traffic signal and any supplemental intersection lighting would be a cost borne by local taxpayers. 8. EFFECTS TO OTHER ENVIRONMENTAL RESOURCES The installation of a traffic signal or roundabout at the intersection of South Willson and College Street would not cause any effects to the following resources or environmental concerns: • Prime, Unique and Important Farmlands • Threatened/Endangered Wildlife • Rare and Sensitive Plant Species • Wildlife Resources and Fisheries • Migratory Birds (E.O. 13186) • Invasive Species (E.O. 13112) • Wetlands (E.O. 11990) • Stream Modifications • Water Quality • Floodplains (E.O. 11988) • Hazardous Waste • Land and Water Conservation Fund Section 6(f) Sites COMPARISON OF DESIGN OPTIONS -44- PART IV: Effects to Cultural Resources A. Effects to the Bon Ton Historic District The College-Willson intersection lies within the southern portion of the Bon Ton Historic District which was listed on the NRHP in October 1987. The Bon Ton Historic District is generally bounded by Olive Street to the north, Cleveland Street to the south and Fourth Avenue to the west. The eastern boundary encompasses properties adjoining the east side of South Willson Avenue but does not extend to South Tracy Avenue. The Bon Ton Historic District contains some of Bozeman’s finest examples of historic residential architecture and includes Italianate, Queen Anne, Colonial Revival, Bungalow/Craftsman, and Late Victorian style residences dating from the early 1880’s to the 1930’s. The project area is located within the existing Bon Ton Historic District (24GA954) in Bozeman. The historic district was listed on the National Register of Historic Places (NRHP) in October 1987 and consists of 189 contributing and primary buildings. Three buildings that contribute to the historic district are located at the College Street/Willson Avenue intersection. They are: the Story Mansion (811 South Willson) at the southwest corner, the Stewart House (804 South Willson) at the southeast corner, and the E. W. King House (725 South Willson) at the northwest corner of the intersection. The City of Bozeman Design Guidelines for Historic Preservation and the Neighborhood Conservation Overlay District identifies the following notable characteristics of the Bon Ton Historic District: • residential neighborhood setting; • diversity of building types; • regularly spaced street trees defining streetscape canopy; • similar front yard setback; • combination of elaborate and vernacular building styles; • porches address the street; • secondary structures and garages to the rear of the lot; and • automobile access primarily from the alley Project Area COMPARISON OF DESIGN OPTIONS -45- The following questions were posed as a way to assess the potential effects of installing a traffic signal or modern roundabout at the College-Willson intersection. Would the design option remove any historic buildings or associated building features that are important in defining the historic character of the setting? SIGNALIZED INTERSECTION MODERN ROUNDABOUT NO. The signalized intersection layout would not remove or affect any historic buildings or building features important in defining the historic character of the setting in the Bon Ton Historic District. No new right-of-way would be required for the proposed signal. NO. The roundabout would not remove or affect any historic buildings or any building features important in defining the historic character of the setting in the Bon Ton Historic District. Minor amounts of new right-of-way would be required from all four corners of the intersection. Would the design option change any of the following elements associated with the setting of the Bon Ton Historic District? o Relationships of buildings to each other o Setbacks o Fencing patterns o Street configuration and traffic patterns o Driveways and walkways o Street trees or other landscaping o Decorative elements such as sculpture, statuary or monuments SIGNALIZED INTERSECTION MODERN ROUNDABOUT Relationships of buildings to each other - NO Setbacks - NO Fencing patterns- NO Decorative elements such as sculpture, statuary or monuments - NO Street configuration and traffic patterns. YES. The existing four-way grid intersection would be maintained but modified to provide a left turn lane for northbound traffic on Willson. The proposed design would use pavement markings to delineate changes in lane configurations and on-street parking lanes along Willson. Lane tapers would be designed for 25 mph traffic through the intersection. While traffic signals provide significant safety benefits, they introduce delays to through movements – this will be notable on Willson Avenue since northbound or southbound Relationships of buildings to each other - NO Setbacks - NO Fencing patterns- NO Street configuration and traffic patterns. YES. The historic four-way intersection would be replaced with a modern roundabout. Splitter islands would be installed along all four approaches to the intersection. This would be the only roundabout on Willson Avenue and in the Bon Ton Historic District (and first modern roundabout on a major street in Bozeman). The roundabout would be a departure from the grid intersection configurations originally laid out for this neighborhood and elsewhere in the Historic District. Traffic on College Street would not be COMPARISON OF DESIGN OPTIONS -46- traffic was not previously required to stop. Traffic delays could deter some facility users to choose other alternate streets without signals. It is unlikely that a signal at the intersection would result in significant shifts in traffic to other nearby residential streets. Notable traffic shifts to neighboring streets would be unlikely since the narrow width, extent of on-street parking, and less direct routing would not result in major savings in travel times over the use of Willson. The City has also indicated it is committed to implementing measures to prevent such traffic shifts to adjoining streets in the neighborhood. Traffic lights can contribute to speeding problems as some drivers will speed up to make it through a traffic light or accelerate quickly after stopping for the light. With signalization and the provision of a left turn lane for northbound traffic, analysis suggests that queues 13 to 19 vehicles long would be expected on the Willson Avenue approaches during the peak hour in 2014. The length of queues at the light would be less during the remainder of the day. As previously discussed, 15 on-street parking spaces would be lost – with the majority of lost parking spaces being in front of the Story Mansion property. Driveways and walkways. YES. The proposed signalized intersection design would not eliminate any residential driveways. For residents backing out of their driveways, the proposed design should be as safe as the existing situation. A 10-foot buffer area (parking lane) separates the traveled way from the curb. Driveway use in the vicinity of the intersection would be inhibited for short periods when queues of vehicles stopped for the signal extend far enough to block driveways. Such driveway impacts would be likely only during peak hours and only when Willson traffic is stopped by the signal. The existing bulb-outs would be removed at all four corners and the curb radius on the west side of Willson at College would be required to stop at the intersection as done for many years. Side street traffic on College would enter the intersection and yield to oncoming vehicles. It is unlikely that the roundabout would significantly change traffic patterns. Willson is an important arterial street in the community and represents one of the most direct routes for those commuting between residential areas on the southeastern portion of the city (and adjoining outlying county areas) and downtown Bozeman. Traffic shifts to neighboring streets would be unlikely since the narrow width, extent of on-street parking, and resulting travel speeds would be less than on Willson. Parking would have to be restricted for approximately 80-100 feet on each corner of the intersection to accommodate the roundabout. As described in detail earlier, a total of 20 on-street parking spaces could be lost with the roundabout. Driveways and walkways. YES. Two driveways accessing directly onto Willson (one north of the intersection on the west side and one south of the intersection on the east side) exist in areas where street narrowing would occur and where splitter islands for the roundabout would be installed. Driveway access at these locations would be perpetuated with the proposed roundabout design. However, the splitter islands would change accessibility to these driveways for residents by inhibiting left turns from Willson into these driveways. Residents would be able to make right turns into the driveways and still be required to back out into oncoming traffic. Queue formation on the north and south COMPARISON OF DESIGN OPTIONS -47- modified to accommodate turns by school busses. New curb ramps would be constructed at the intersections to facilitate handicapped access. New driveway approach aprons would be constructed in the boulevard areas and the sidewalk through affected driveways would be replaced as necessary. Button-activated pedestrian signals (with Walk-Don’t Walk indicators) and crosswalks would be installed on all four legs of the intersection. Street trees or other landscaping. YES. The proposed signalized intersection layout would not remove any street trees. However, some trees may need to be trimmed to avoid conflicts with new signal poles on the corners of the intersection. A minor amount of the existing boulevard would be lost due to the placement of signal poles and associated hardware. Decorative elements. YES. One existing street light along Willson would have to be removed and reset. approaches to the roundabout should not block driveways since traffic can continually move. The roundabout would slow travel speeds on Willson making backing maneuvers from the affected driveways somewhat safer. The proposed roundabout configuration would require substantial modifications to the pedestrian facilities at this intersection. The existing bulb-outs and adjoining curbing would be removed at all four corners and areas of existing sidewalk on each corner would be removed. Approximately 50 feet of existing sidewalk along College Street and 50 feet of existing sidewalk along Willson Avenue would need to be removed for the roundabout on each corner. New sidewalk would be installed along the roundabout. The location of pedestrian crossings at the intersection would also be shifted. Street trees or other landscaping. YES. Trees growing in the area between the existing curb line and new curb line for the roundabout in the northwest, northeast, and southwest quadrants of the intersection would need to be removed since they would lie within the circulatory roadway for the roundabout. It was also assumed trees would need to be removed if they were located extremely close to the new curb line. Five trees along the south side of College Street east of Willson would be lost if a replacement on-street parking and a drop- off/pickup area for the Children’s Development Center were constructed in the existing boulevard. In total, between 9 and 12 trees may be lost due to the installation of the proposed roundabout. The loss of between 9-12 mature trees would be a notable visual change in the vicinity of the intersection. The street canopy created by the existing trees at the intersection would be lost. Decorative elements. YES. The existing street lights along Willson are unique design elements of the streetscape and contribute to the character of the Bon Ton Historic District. Existing street lights would need to be removed from the northeast and COMPARISON OF DESIGN OPTIONS -48- southwest corners of the existing intersection to accommodate the development of a roundabout. The light post on the southwest corner could be reset close to its original position but the light post on the northeast corner would have to be moved some 25 feet to the north. Resetting the light posts would change the spacing interval and relationships between adjoining light fixtures along Willson to the north and south of the proposed roundabout. The center island of the roundabout would be a new architectural element introduced into the Historic District. Plantings or other treatments within the center island can serve as a neighborhood enhancement and help identify the area as a special place in the City. There are no other intersections in the Historic District with notable decorative elements. Would the design option introduce new features or materials into the historic district? SIGNALIZED INTERSECTION MODERN ROUNDABOUT YES. The most notable feature introduced into the historic district would be the traffic signal itself. Pedestals for attaching mast arm support poles and mast arms would be installed on each corner of the intersection. Chapter 12 (Traffic Signal Design) of MDT’s Traffic Manual (July 1999) provides general design parameters for signal installations and section 12.4.1.1 states: “Where practical, MDT prefers the use of cantilever, mast-arm mounted signal heads that are vertically oriented in a 3 or 4 lens configuration with one signal head per lane and a supplemental signal head mounted on the mast arm support pole. Lens size is typically 300 mm (12 inches) in diameter. Vertical clearance for new signal installations is 17.5 feet above the pavement surface.” YES. The roundabout is a “new” form of intersection control for this area so the overall design and individual elements associated with the roundabout would be considered as newly introduced features in the Bon Ton Historic District. Although specific design details have not been identified, the roundabout would introduce a new type of streetscape to the district and could employ some materials (patterned concrete, brick, etc.) in splitter islands and center island that have not been previously used at other intersection locations within the District. Raised curbing for splitter islands on each approach and for the center island would be new elements within the street. Raised medians are not used anywhere else in the neighborhood. Any landscaping associated with the center median would be a newly introduced feature. COMPARISON OF DESIGN OPTIONS -49- A typical cantilevered mast arm signal installation is shown below: Typical cantilevered mast arm signal installation. Pedestrian crossing signals with push button controls would also be installed on the mast arm support poles. Traffic signals also require the installation of an above-ground signal controller to program the phasing of the signal. The typical controller installation is shown below: The traffic signal controller would be installed on the southwest corner of the intersection (Story Mansion corner). Additional street lighting and signing necessary for the safe operation of the roundabout would also be newly introduced features. Typical signing and pavement markings for each approach of a roundabout is shown below: Typical signing layout on roundabout approach. Typical pavement markings on roundabout approach. Signal controller Pedestrian signal buttons COMPARISON OF DESIGN OPTIONS -50- Other visible elements associated with the traffic signal at the intersection would be electrical power connections from existing poles to the signal installation and pull boxes for wiring on each corner behind the curb line. The pull boxes would be even with or slightly higher than the ground surface in the boulevards. Additional street lighting may desirable at this signalized intersection. The street lights could be considered as newly introduced features in the historic district. (NOTE: The recently installed signal at Olive Street- Willson did not include any new overhead street lighting and perpetuated existing concrete street lights on the northeast and southwest corners of the intersection). Additional crosswalk markings and advanced signing would be installed at the intersection. Currently, pavement markings and signing exist only for a crosswalk for Willson Avenue located on the north side of the intersection. Would the new features or materials be visually incompatible with or destroy historic relationships within the setting of the district? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The traffic signal would be a new feature in the South Willson residential neighborhood and this portion of the Bon Ton Historic District. However, this would not be the first signal in the historic district since a signal was recently installed at Willson and Olive. The signal at Willson and Olive is located in a transitional part of the district between the downtown and the adjoining residential area to the south. MDT has proposed using black, powder- coated mast arm support poles and mast arms similar to the ones used at Willson and Olive Street. There are also opportunities to incorporate decorative support poles, mast arms, and light posts to help make the signal more compatible with the existing streetscape in the district. However, The Secretary of the Interior's The roundabout would be an entirely new form of intersection treatment in the Bon Ton Historic District as well as in other old residential neighborhoods in the City. There is no precedent for the use of roundabouts in the historical development of this area. In this respect, a roundabout would seem to be incompatible with the setting of the historic because it replaces a four-way intersection, the type of street intersection found everywhere else in the district (and in other historic districts comprised primarily of long- time residential neighborhoods). The loss of street trees the intersection due to the construction of the roundabout would be a very notable change and would negatively affect to the appearance of the streetscape in this portion of the historic district. The Secretary of the Interior’s Standards for Rehabilitation advise against COMPARISON OF DESIGN OPTIONS -51- Standards for Rehabilitation cautions against changes that create a false sense of historical development. It is possible that adding decorative signal support poles, mast arms, or light posts could be viewed as adding features that are not historically appropriate for the district. The project is being proposed to remedy a documented accident problem at a specific location on the City’s street network. Traffic has and will continue to increase on Willson Avenue through the heart of the Bon Ton Historic District with or without the proposed signal and the need to control traffic at this intersection will persist. Neighborhood residents and others have adamantly contended that a traffic signal will change the character of the historic district, adversely affect property values, and be the stimulus for commercial uses to enter the neighborhood. These sentiments suggest that at least in the views of these Bozeman residents, the signal would be incompatible with the setting of the historic district. removing a historic building, building feature or landscape feature that is important in defining the historic character of the setting. In this respect, the tree loss would go against the Secretary’s guidance. Additional street lighting and new signing for the roundabout could be viewed as being incompatible with the setting of the historic district. New street lights may need to be notably taller than existing street lights to function properly and light poles would likely not be made of concrete. Roundabouts typically have more and different guidance signs than needed for standard intersections. These signs would have to be installed within the boulevards and splitter islands on each approach and in the center island. Typical approach signing and pavement markings for a single lane urban roundabout are shown on the following page. Residents of the South Willson neighborhood appear to favor the roundabout treatment over a signal due to its potential traffic calming benefits. Arguments have not been heard in public meetings that suggest a roundabout would change the character of the historic district. Would the elements associated with the option be designed in a manner that makes clear what is historic and what is new? SIGNALIZED INTERSECTION MODERN ROUNDABOUT YES. It is believed the signal and other intersection modifications would be done in a way that allows old and new features of the district to be readily identified. YES. Because the design and features of the roundabout would be substantially different from the existing streetscape, it would be obvious at this intersection what is historic and what is new. Some elements of the roundabout design, like new street lights, could be selected based on a compatible appearance with existing features. The following sections discuss potential effects to specific features contributing to the Bon Ton Historic District including street trees and boulevards, historic street lighting, and sidewalks. COMPARISON OF DESIGN OPTIONS -52- 1. IMPACTS TO STREET TREES The streetscape of the project area is characterized by regularly spaced trees planted in the boulevards along College Street and Willson Avenue. The City of Bozeman Design Guidelines for Historic Preservation and the Neighborhood Conservation Overlay District indicates that as a general policy, the traditional character of the streetscape should be maintained. The City’s Design Guidelines call for the continuation of the pattern of street trees and offer the following recommendations concerning street trees: • Existing street trees should be preserved, when feasible. • If a new detached sidewalk is to be created, street trees should be an accompanying feature. • If a new sidewalk is to be installed, it should detour around mature street trees, when feasible. • When an existing street tree dies, it should be replaced. • Any new developments should include street trees. • The historic urban design character for street tree placement should be considered when enforcing city street standards. How would the design option affect street trees in the district? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The proposed signalized intersection configuration would not require the removal of any street trees. However, trees may need to be trimmed to avoid conflicts with new signal poles on each corner of the intersection. The proposed roundabout configuration would require the removal of mature trees in the four quadrants of the intersection due to the construction of new curbs and sidewalks for the roundabout. In total, between 9 and 12 trees may be lost due to the installation of the proposed roundabout. Removing this many mature trees would be a notable visual change in the vicinity of the intersection. The street canopy created by the existing trees at the intersection would be lost. The potential loss of trees could affect the setting for individual properties near the intersection that are on or potentially eligible for the NRHP. The most notable of such effects would be on the northwest corner (potential loss of 3 trees) and on the southeast corner (potential loss of 6 trees). COMPARISON OF DESIGN OPTIONS -53- 2. IMPACTS TO HISTORIC STREET LIGHTS Historic street lights exist along Willson Avenue in the project area. The street lights, consisting of tapered fluted concrete posts with opaque glass tops, are about 10 feet in height and placed in a staggered fashion along the east and west sides of Willson. These features were installed in 1935 along both South Willson and West Cleveland Street. An example of the historic street light fixtures found near the College-Willson is shown below. Street lights along Willson Light posts at SW and NE corners The City of Bozeman Design Guidelines for Historic Preservation and the Neighborhood Conservation Overlay District advocates protecting and maintaining significant features and stylistic elements within the City’s historic neighborhoods. Since this style of street lighting represents a unique design element of the streetscape and contributes to the character of the Bon Ton Historic District, it is assumed that the affected light posts would need to be salvaged and reset with the development of a roundabout. What impacts would the design option have on the historic street lights in the district? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The street light on the northeast corner would have to be removed and reset some 20 feet to the north. Resetting the light post would not substantially change the spacing interval and relationships between adjoining light fixtures along Willson. Signal installations typically include street lights mounted on the tops of signal support posts on two or more corners of the intersection. The recently installed signal at Olive Street-Willson did not include new overhead street lighting and instead perpetuated existing concrete street lights on the northeast and southwest corners of the intersection. Historic street lights would need to be removed from the northeast and southwest corners of the existing intersection to accommodate the development of a roundabout. The light post on the southwest corner could be reset close to its original position but the light post on the northeast corner would have to be moved some 25 feet to the north. Resetting the light posts would change the spacing interval and relationships between adjoining light fixtures along Willson to the north and south of the proposed roundabout. Two existing light posts (one on the west side of Willson north of the intersection and one on east side of Willson south of the COMPARISON OF DESIGN OPTIONS -54- intersection) would not need to be moved for the roundabout. However, they would be situated further away from the street because the curb line would be revised on the north and south approaches to the roundabout. FHWA guidance indicates that for roundabouts to operate safely and efficiently, drivers must be able to enter the roundabout move through circulating traffic and separate from the circulating traffic stream in a safe and efficient manner. Motorists approaching at night must be able to see that the intersection has a central island and that one can no longer drive straight through the intersection. Good street lighting is also needed so that cyclists, motorcyclists, and pedestrians can be seen in the roundabout and on the approaches at night. A review of literature on the this topic suggests that additional street lights are typically installed at roundabouts and on the approaches back a distance of over 150 feet from the yield lines. Street lights evenly spaced around the outside of roundabouts and along the approaches to roundabouts (back to the beginning of the splitter islands) appears to be a preferred lighting scheme. European roundabout experience also stresses the importance of ensuring that roundabout light levels are higher than the levels on approach roads and streets. Therefore, implementing a safe, modern roundabout at the Willson and College intersection would likely require changes to street lighting to ensure the safety of motorists and other street users. Such changes could include the use of taller light posts and possibly brighter lights at the intersection. COMPARISON OF DESIGN OPTIONS -55- B. Effects to Historic Properties at the Intersection 1. POTENTIAL EFFECTS TO THE STORY MANSION The Story Mansion (T. Byron Story House) represents the most notable residence in the southern portion of the Bon Ton Historic District. The Story Mansion, located at 811 South Willson, is situated southwest of the existing intersection on property encompassing a full city block. The structure, which once served as the SAE Fraternity House, is listed on the National Register of Historic Places. The Victorian-style home was built in 1910 by builder John Scahill and designed by Helena architect C.S. Haire, the architect responsible for the design of Montana’s State Capitol. Architect Fred F. Willson acted as supervising architect. The home was built for Thomas Byron (T.B.) Story. The Story Mansion was acquired by the City of Bozeman in 2003 and is currently undergoing exterior renovations. The eventual future use of the Story Mansion is unknown at this time, although proposals ranging from commercial uses to a community center have been discussed for the property. What impacts would the design option have on the Story Mansion and its associated property? SIGNALIZED INTERSECTION MODERN ROUNDABOUT The signalized intersection configuration would require the placement of a signal pole in the boulevard at the southwest corner of the intersection – the northeast corner of the Story Mansion site. The boulevard is within the existing right-of-way for College Street and Willson Avenue. A pedestal-mounted traffic signal controller would be installed on the southwest corner of the intersection (within the existing boulevard of the Story Mansion). A pull box for wires would be installed in the boulevard near the intersection. The pull box would be at or slightly above the ground surface. The curb bulb out at the southwest corner of the intersection would have to be removed and a new curb radius with handicapped ramps provided at this location. Additional marked pedestrian crosswalks would be added to the south side of the intersection and both sides of College Street. The development of a roundabout would not physically impact the historic residence or associated structures. However, developing a roundabout would require an estimated 545 square feet of new right-of-way from the northeast corner of the Story Mansion property. The new right-of-way would not need to be purchased since the property is owned by the City. Two trees near the intersection would likely be removed since they lie in the area occupied by the circulatory roadway for the roundabout or very near the new curb line. A historic street light within the boulevard along Willson would likely have to be removed and reset further to the south. Approximately 50 feet of existing sidewalk along College Street and 50 feet of existing sidewalk along Willson Avenue would need to be removed for the roundabout. New sidewalk would be installed along the roundabout. The location of pedestrian crossings at the intersection would also be shifted. COMPARISON OF DESIGN OPTIONS -56- Two trees near the intersection may need to be trimmed to avoid conflicts with new signal poles on each corner of the intersection. With the exception of space for two parked vehicles north of Harrison Street, there would be no on-street parking along Willson in front of the Story Mansion. In total, 10 on-street parking spaces along Willson would be lost. The project would introduce traffic signal poles with overhead mast arms into the setting of Story Mansion property. The signal would be the first traffic light installation in this part of the Bon Ton Historic District. Traffic would periodically stop along Willson Avenue in front of the Story Mansion due to the operation of the new signal. Vehicle queues would form during peak hours. The existing four-way grid intersection at the northeastern edge of the property would be replaced with a modern roundabout. Splitter islands would be installed along College and Willson adjacent to the Story Mansion property. This would be the only roundabout on Willson Avenue or in the Bon Ton Historic District. Parking would have to be restricted for approximately 80-100 feet at each corner of the intersection. Five on-street parking spaces would be lost along Willson in front of the property. The removal of 2 mature trees from the boulevard at the southwest corner of the intersection, changes to the sidewalk, and resetting a historic street light are apparent visual changes to the setting of the property. Trees would also be lost from the other three corners of the intersection. Additional street lighting for the roundabout, particularly taller lights or more intense lights, could change the night-time setting of the neighborhood near the Story Mansion. Similarly, roundabouts typically require more and different signing to help motorists negotiate the new intersection layout. The roundabout can be appealing as an architectural element with plantings or other treatments that can enhance the neighborhood. The lower traffic speeds on Willson and efficient operation of the roundabout could make this area more pleasant to live along. Depending upon the ultimate use of the Story Mansion, a roundabout may enhance the use of the property by making access to and from the property from College safer and more efficient. COMPARISON OF DESIGN OPTIONS -57- 2. EFFECTS TO OTHER PROPERTIES Three buildings that contribute to the historic district are located at the College Street/Willson Avenue intersection. They are: the Story Mansion (811 South Willson) at the southwest corner, the Stewart House (804 South Willson) at the southeast corner, and the E. W. King House (725 South Willson) at the northwest corner of the intersection. The Sigma Chi fraternity house at the northeast corner of the intersection does not contribute to the historic district. What potential effects would the design option have on individual properties near the intersection? SIGNALIZED INTERSECTION MODERN ROUNDABOUT E.W. King House (725 S Willson) Installing a signal would not require any new right-of-way from the property. A new signal mast arm support pole with cantilevered mast arm and a pull box would be installed in the boulevard area at the corner. Minor tree trimming may be needed at the corner to eliminate conflicts with the signal mast arm. The existing curb bulb at the northwest corner would be removed and a new curb radius would be constructed. Modifications to the existing sidewalk at the corner would be required and new handicapped access ramps and would be installed. Due to a slight shift in the travel lane, on- street parking on Willson would be lost in front of this residence between the corner and the existing driveway. E.W. King House (725 S Willson) Developing a roundabout at this intersection would require an estimated 800 square feet of new right-of-way from the property. This is the corner with the most new right-of-way acquisition for the roundabout design. The roundabout would require making modifications to the curb line in front of the home and would result in a slightly wider boulevard. It is possible a short section of new sidewalk would be needed between the street and existing sidewalk at the new pedestrian crossing locations. Approximately 50 feet of existing sidewalk along College Street and 50 feet of existing sidewalk along Willson Avenue would need to be removed for the roundabout. New sidewalk would be installed along the roundabout. The new sidewalk would be slightly closer to the residence and be developed in a curved configuration to follow the curb radii of the roundabout at the southeast corner of the property. The location of pedestrian crossings at the northwest quadrant of the intersection would also be shifted. Two trees near the intersection would need to be removed since they would lie in the area occupied by the circulatory roadway. A third tree is located very near the new curb line and in the vicinity of the relocated pedestrian crossing on College. Signing for pedestrian crossings and the roundabout would be likely in the boulevard COMPARISON OF DESIGN OPTIONS -58- Stewart House (804 South Willson) Installing a signal would not require any new right-of-way from the property. A new signal mast arm support pole with cantilevered mast arm and a pull box would be installed in the boulevard area at the corner. Minor tree trimming may be needed at the corner to eliminate conflicts with the signal mast arm. The existing curb bulb at the southeast corner would be removed and a new curb radius would be constructed. Modifications to the existing sidewalk at the corner would be required and new handicapped access ramps and would be installed. The on-street parking situation would not change. 722 South Willson – Sigma Chi fraternity house Installing a signal would not require any new right-of-way from the property containing the Sigma Chi fraternity house. A new signal mast arm support pole with cantilevered mast arm and a pull box would be installed in the boulevard area at the corner. A historic street light would have to be removed and reset further north. The existing curb bulb at the northeast corner would be removed and a new curb radius would be constructed. Modifications to the existing sidewalk at the corner would area approaching the reconfigured intersection. On-street parking along Willson in front of the residence would be lost. Stewart House (804 South Willson) Developing a roundabout at this intersection would require an estimated 545 square feet of new right-of-way from the property. The impacts to the existing sidewalk would be similar to those on other corners of the intersection. New sidewalk would be installed and the location of pedestrian crossings at the southeast quadrant of the intersection would also be shifted. All on-street parking would be lost in front of the residence (on Willson). A replacement dropoff/pickup location and on-street parking area could be provided along the south side of College if a portion of the existing boulevard were removed. Two trees at the corner would need to be removed to accommodate the roundabout. Four additional trees along the south side of College Street east of Willson would be lost if the boulevard area is removed to provide on-street parking and a drop-off/pickup area. 722 South Willson – Sigma Chi fraternity house Developing a roundabout at this intersection would require an estimated 545 square feet of new right-of-way from the property containing the Sigma Chi fraternity house. The impacts to the existing sidewalk would be similar to those at 725 South Willson. New sidewalk would be installed and the location of pedestrian crossings at the northeast quadrant of the intersection would also be shifted. Minor revisions would be required to sidewalk areas in front of the fraternity house to match the new curb line. It is possible a short section of new sidewalk would be needed between the street and existing sidewalk at the new pedestrian COMPARISON OF DESIGN OPTIONS -59- be required and new handicapped access ramps and would be installed. The on-street parking situation would not change. 810 South Willson – residence Signalizing the intersection would have no direct impacts on this property. There would be no impacts to the existing sidewalk or street trees in front of the home. The on-street parking situation would not change with the proposed signal. crossing locations. A historic street light would have to be removed and reset further north of the roundabout. One tree near the intersection would need to be removed since they would lie in the area occupied by the circulatory roadway. About 6 on-street parking spaces would be lost along Willson and College adjacent to the fraternity house. A portion of the existing boulevard along the north side of College may have to be removed to retain several on-street parking spaces. 810 South Willson – residence Developing a roundabout at this intersection would not require any new right-of-way from the property. There would be no impacts to the existing sidewalk or street trees in front of the home. However, the roundabout would require making modifications to the curb line in front of the home and would result in a slightly wider boulevard. The existing driveway and sidewalk would have to be extended slightly to match the new curb line. One on-street parking space would likely be lost in front of the residence. C. Section 106 Considerations Section 106 of the National Historic Preservation Act of 1966 requires Federal agencies (FHWA in this case) to consider the effects of their undertakings on historic properties. The review process is administered by the Advisory Council on Historic Preservation (ACHP), along with the Federal Highway Administration (FHWA/MDT) and the State Historic Preservation Office (SHPO). The historic preservation review process mandated by Section 106 is outlined in regulations issued by the ACHP. The revised regulations, "Protection of Historic Properties" can be found in 36 CFR Part 800. The section 106 process attempts to accommodate historic preservation concerns with the needs of Federal undertakings through consultation among the agency official and others with an interest in the effects of the undertaking on historic properties. The goal of consultation is to identify historic properties potentially affected by the undertaking, assess its effects and seek ways to avoid, minimize or mitigate any adverse effects on historic properties. COMPARISON OF DESIGN OPTIONS -60- Historic properties are those that are listed on, or are eligible for inclusion in, the National Register of Historic Places (NRHP). Once eligible historic properties have been identified, it is then determined whether the proposed undertaking could affect the properties. The criteria of effect and adverse effect are used to determine potential effects on historic properties. The criteria of adverse effect states that “an adverse effect is found when an undertaking may alter, directly or indirectly, any of the characteristics of a historic property that qualify the property for inclusion in the National Register in a manner that would diminish the integrity of the property’s location, design, setting, materials, workmanship, feeling, or association… Adverse effects may include reasonably foreseeable effects caused by the undertaking that may occur later in time, be farther removed in distance or be cumulative.” [36 CFR 800.5(a)] When applying the criteria of effect and adverse effect, there are three possible findings: ƒ No Effect: There is no effect of any kind, neither harmful nor beneficial, on the historic properties. The proposed undertaking may proceed. ƒ No Adverse Effect: There could be an effect, but the effect would not be harmful to those characteristics that qualify the property for inclusion in the NRHP. Project documentation must be submitted to the Council for concurrence. ƒ Adverse Effect: There could be an effect, and that effect could harm characteristics that qualify the property for inclusion in the national register. FHWA and MDT must begin consultation with the SHPO and the ACHP to seek ways to avoid, minimize, or mitigate the adverse effects. The agency consults to resolve adverse effects with the SHPO and others (including local governments and the public). The ACHP may choose to participate in consultation in some cases. Consultation usually results in a Memorandum of Agreement (MOA), which outlines agreed-upon measures that the agency will take to avoid, minimize, or mitigate the adverse effects. In some cases, the consulting parties may agree that no such measures are possible, but that the adverse effects must be accepted in the public interest. If an MOA is executed, the agency proceeds with its undertaking under the terms of the MOA. Has there been a preliminary Determination of Effect made for each design option? MDT submitted a Determination of Effect for this project to the Montana SHPO on May 1, 2006. The Determination was made for the two design options under consideration for the project. These Determinations are summarized below: SIGNALIZED INTERSECTION MODERN ROUNDABOUT There would be No Adverse Effect to the National Register-listed Bon Ton Historic District (24GA954) as a result of the proposed project. The proposed Roundabout option under consideration for the intersection of College Street and Willson Avenue would have an Adverse Effect to the Bon Ton Historic District and the historic properties that contribute to it in the immediate vicinity of the project. COMPARISON OF DESIGN OPTIONS -61- The principal reasons for this determination include: o The signal poles, mast-arms, signals, and the control box would all be installed within the existing right-of-way. There would not be any encroachment on historic buildings or features near the College Street/South Willson intersection. o None of the existing trees would be removed, although a few may be trimmed back to avoid conflicts with the signal poles. o The existing 4-way grid system streets and intersection would be perpetuated in their existing configuration. The modification on the west side of Willson would be minimal and not constitute a significant change in the appearance of the intersection. All markings delineating the northbound turn-bay would be placed on the pavement and not consist of raised islands. o The installation of the traffic signal would not significantly compromise the setting of individual contributing properties near the intersection. o The proposed signals are not the first to be installed in the district. In 2004, the City of Bozeman installed traffic signals in the Bon Ton Historic District at the intersection of Willson Avenue and Olive Street. The MDT proposes to install traffic signals of similar appearance at the College Street/Willson Avenue intersection. o The support poles and mast-arms would introduce materials that are not historic to the district. It is the intent of the MDT, however, to use poles and arms that are black and powder-coated to help blend them into the neighborhood. The factors supporting this determination include: o The roundabout would be an entirely new form of intersection treat in the Bon Ton Historic District (24GA954). There is no precedent for the use of a roundabout in an historic district in Bozeman. o Because of the design features, the roundabout would be significantly different from the existing streetscape by placing a round feature within an historic grid pattern street system. o The roundabout would require substantial amounts of new right-of- way at each of the four quadrants of the intersection. The circular configuration of the roundabout would result in the reconstruction of sidewalks and boulevards at the intersection to make them conform to the new layout. This would also be a deviation from the traditional grid pattern of the historic district and result in wider boulevards and sidewalks located closer to historic properties built to conform to the roundabout. o Approximately 9 to 12 mature trees located in the boulevards but associated with the historic properties would have to be removed. The mature trees in the boulevards have historically provided a screen between the historic properties and the street and, more importantly, helped define the historic character of the historic district. Their loss would significantly change the appearance of the neighborhood. o Two historic lampposts would have to be relocated, which would upset the staggered configuration and spacing between other lampposts on Willson Avenue in the historic district. COMPARISON OF DESIGN OPTIONS -62- o Additional street lighting would have to be added to the intersection to make the roundabout safer. The roundabout would also require significantly more regulatory and guidance signage on each approach. Considered together, these impacts and the addition of modern street features would significantly diminish the historic character and appearance of the neighborhood. MDT received a letter from SHPO on May 8, 2006 concurring with the determinations that the signalized intersection option would have No Adverse Effect to the Bon Ton Historic District and that the roundabout design would have an Adverse Effect to the District. A copy of SHPO’s letter can be found in Attachment 2. D. Section 4(f) Considerations Section 4(f) of the 1966 Department of Transportation Act (49 U.S.C. 303) provides for the protection of publicly-owned parks, recreation lands, historical sites, and wildlife and waterfowl refuges. The proposed intersection improvements would not affect any public parks, recreation lands, or wildlife or waterfowl refuges. However, the College-Willson intersection is located in the NRHP-listed Bon Ton Historic District (24GA0954) and adjacent to other properties near the intersection that are individually eligible for the NRHP. The FHWA cannot approve the use of land from any significant historic site unless a determination is made that: 1) there is no feasible and prudent alternative to the use of land from the property; and 2) the action includes all possible planning to minimize harm to the property resulting from such use. A Section 4(f) “use” occurs when: • Land from a 4(f) site is permanently incorporated into a transportation facility through the purchase of right-of-way or sufficient property interests have been otherwise acquired to implement the project. • There is a temporary occupancy of land that is adverse; or • There is a constructive use of land. Constructive use only occurs in those situations where the proximity impacts of a project on the 4(f) property substantially impair features or attributes that qualify the property or resource for protection under Section 4(f). The use of Section 4(f) property requires that MDT, in coordination with the FHWA, document potential effects on the property associated with the proposed action; alternatives considered to avoid or minimize impacts; mitigating measures; and coordination efforts. This documentation can take the form of either a programmatic or an individual Section 4(f) Evaluation. Within a National Register listed (or eligible) historic district, Section 4(f) applies to the use of those properties that are considered contributing to the eligibility of the historic district, as well as any individually eligible property within the district. With the signal option, MDT could use a programmatic evaluation form, known as the Final Nationwide Section 4(f) Evaluation and Approval for Federally-Aided Highway Projects with Minor Involvements with Historic Sites, for the minor use of 4(f) property from the Bon Ton COMPARISON OF DESIGN OPTIONS -63- Historic District. This programmatic evaluation is applicable for projects that improve existing highways and use minor amounts of land from 4(f) sites adjacent to existing highways. The impact on the Section 4(f) site resulting from the use of the land must be considered minor. The word “minor” is defined in the applicability criteria for the programmatic evaluation as having either a “no effect” or “no adverse effect” on the qualities which qualified the site for listing or eligibility on the NRHP. An “individual” (or long-form) Section 4(f) Evaluation would need to be prepared for roundabout design option. A programmatic 4(f) evaluation would not be applicable because the roundabout would remove or alter historic objects within the historic district. Additionally, the “adverse” effect determination for impacts to the historic district is not considered a minor use of land from the 4(f) site as defined in the applicability criteria (#5) for the programmatic evaluation. Coordination with FHWA will occur as the project develops to establish 4(f) evaluation needs and processing requirements. E. Local Historic Preservation Considerations In January 2006, the City adopted the City of Bozeman Design Guidelines for Historic Preservation and the Neighborhood Conservation Overlay District which established a set of design guidelines for restoration and rehabilitation of existing structures and new construction within Neighborhood Conservation Overlay and the Historic Districts. The primary preservation goal of the design guidelines is to preserve the integrity of its individual historic structures and the character of its streetscapes in the Neighborhood Conservation Overlay District. The Department of Planning and Community Development administers the Design Guidelines. In doing so, they consider how each proposed project meets the guidelines and how the proposed work would therefore help to accomplish the design goals set forth in Design Guidelines and in the Unified Development Ordinance. A project may fall into a special review category because of its size or design complexity. In this case the Historic Preservation Advisory Board (HPAB) and/or the Design Review Board (DRB) may be consulted to advise City Staff on the appropriateness of the project design. The Design Guidelines generally require that the proposed activities in the Neighborhood Conservation Overlay District be reviewed for compatibility with The Secretary of the Interior's Standards for Rehabilitation. It is assumed that whatever design option is selected must be reviewed by the City’s Historic Preservation Advisory Board (HPAB) and/or the Design Review Board (DRB) and a Certificate of Appropriateness would be needed. Jon Axline, a historian with MDT’s Environmental Services Bureau, has discussed the potential effects of the signal and roundabout options on the Bon Ton Historic District with Allyson Bristor, the City of Bozeman’s Historic Preservation Planner. Ms. Bristor agreed with the Section 106 Determinations of Effect for the signal and roundabout design options. ATTACHMENT 1: SUPPLEMENTAL CAPACITY ANALYSES ATTACHMENT 2: SHPO LETTER CONCURRING WITH DETERMINATIONS OF EFFECT FOR SIGNAL AND ROUNDABOUT OPTIONS