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HomeMy WebLinkAbout008.1 APPENDIX D 1111 East Broadway, Missoula, MT 59802 I OFFICE 406.728.4611 I EMAIL wgm@wgmgroup.com 11/30/2021 Cody Croskey, P.E. TD&H Engineering 234 E. Babcock Street, Suite 3 Bozeman, MT 59715 Re: 9Ten Mixed Use TIS, Bozeman, MT Dear Cody: WGM Group, Inc. (WGM) prepared the Traffic Impact Study for the 9Ten Mixed Use project (August 10, 2021). This proposed development is located west of North 7th Avenue between West Aspen Street and West Juniper Street in Bozeman, Montana. The TIS was submitted to the City of Bozeman (City) for review and comment. The City’s comments were received via email. The purpose of this letter is to address the City’s comments with the additional information or explanation requested. Comment 1a: LOS must be calculated at the design year a minimum of 15 years following the application. Response 1a: Following discussion with the City Engineering Department it was agreed that the 15-year analysis is no longer required. No further action is required. Comment 1b: A LOS must be established for the intersection as a whole. The Highway Capacity Manual does not offer a LOS evaluation for two-way stop intersections such as Aspen and Juniper intersections with 7th. However, an acceptable approach to compute a LOS for the intersections as a whole would be to provide a weighted average of the available movements LOS. Response 1b: WGM revisited the results of the capacity analysis calculations for the North 7th Avenue intersections with West Juniper Street and West Aspen Street and used the results provided by the HCM analysis to calculate a volume-weighted delay for the intersections as a whole. The results of this analysis are summarized in Table 1. TABLE 1: OVERALL INTERSECTION LOS SUMMARY Peak AM Hour Peak PM Hour 2023 No-Build 2023 Build 2023 No-Build 2023 Build Delay LOS Delay LOS Delay LOS Delay LOS North 7th Avenue & West Juniper Street 0.4 A 0.4 A 0.8 A 0.8 A North 7th Avenue & West Aspen Street 0.1 A 0.4 A 0.7 A 1.2 A Delay is measured in seconds per vehicle. Cody Croskey 11/30/2021 Page 2 of 3 This analysis demonstrates that both the West Juniper Street intersection with North 7th Avenue and the West Aspen Street intersection with North 7th Avenue will operate at an overall LOS A during both the AM and PM peak hours, and that the site-generate traffic adds very little overall delay to these intersections. Comment 2a: The applicant must provide an analysis of what mitigation measures could be utilized to improve the LOS and safety at these intersections. Response 2a: As illustrated in Response 1b, there is virtually no impact to the overall delay or level-of-service at these intersections from the site-generated traffic. Therefore, no mitigation is required. Comment 2b. The applicant must provide crash data at the intersections of West Aspen and West Juniper with North 7th Avenue. The applicant must obtain this data from MDT and Taylor Lonsdale with the City. Response 2b: Crash Data for the three-year period from January 1, 2015 through December 31, 2017 was obtained from the MDT Traffic and Safety Bureau. Crash Data for the three-year period from January 1, 2018 through December 31, 2020 was obtained from the Bozeman Police Department. This six years of data was reviewed to identify areas of traffic safety concern.  North 7th Avenue and Juniper Street: There were no recorded incidents from the MDT data at this location. Six crashes were reported from the Bozeman Police Department at this intersection. Four rear-end collisions with no apparent injury (two southbound, two northbound), one three-vehicle rear-end collision with no apparent injury (northbound), and one unknown collision type with no apparent injury. The five rear-end collisions are all related to queued traffic from nearby signalized intersections.  North 7th Avenue and Aspen Street: Two crashes were reported from MDT at this intersection. One was a right-angle collision in rainy, daylight conditions with no apparent injury and one was a northbound rear-end collision in dry, daylight conditions, with possible injury. Eight crashes were reported from the Bozeman Police Department at this intersection including two three-vehicle rear-end collisions with no apparent injury (both southbound), two rear-end collisions with no apparent injury (one northbound, one unknown), one right-angle collision involving a vehicle turning left onto Aspen Street from northbound North 7th Avenue, one sideswipe collision involving merging traffic in a construction zone, and two unknown collision types with no apparent injury. The only observable crash trend at these intersections is of rear-end crashes resulting from general traffic congestion. Of the 16 reported crashes, 13 provided enough information to determine the crash type. Of these 13, ten (77%) were rear-end crashes. Comment 2c. The applicant must provide a warrant analysis for a pedestrian crossing at the intersection of West Aspen Street and North 7th Avenue. This must determine if a crosswalk should be provided at this intersection including any signs or traffic control devices. Cody Croskey 11/30/2021 Page 3 of 3 Response 2c: A pedestrian crossing at this location is not recommended. A signalized pedestrian crossing already exists at the intersection of North 7th Avenue and West Tamarack Street only one block to the north of Aspen Street. This location includes painted crosswalks, ADA ramps, pedestrian signal heads and pedestrian pushbuttons and provides a protected pedestrian crossing. While the MDT’s Guidance for Determining Pedestrian Crossing Treatment at Uncontrolled Locations leaves the door open to a pedestrian crossing at Aspen Street, given the width of North 7th Avenue and the volume of traffic it serves, MDT would require a rectangular rapid flashing beacon (RRFB), pedestrian hybrid beacon, or pedestrian traffic signal at such a crossing. Any such beacon or signal at Aspen Street would interfere with traffic operations at the existing signalized intersection at Tamarack Street and as such is not recommended. Further justification for not adding a pedestrian crossing at Aspen Street is the lack of significant pedestrian generators such as a trail crossing at this location. Sincerely, WGM Group, Inc. Mark D. Bancale, P.E., PTOE Senior Traffic Engineer MDB:am W:\Projects\210532\TRAFFIC\Traffic Comment Response Letter.docx