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HomeMy WebLinkAbout007.01 - Appendix F.2 - Traffic Impact Study Update March 8, 2024 Kyle Scarr, PE TD&H Engineering 234 E Babcock Street, Suite 3 Bozeman, MT 59715 Reference: 8 Aspen Development TIS, Bozeman, MT Project No. 23505 Dear Kyle: The purpose of this letter is to provide a response to comments received from the City of Bozeman regarding the 8 Aspen Development TIS (January 2024) for the proposed residential and commercial development in Bozeman, Montana. Access Control It was requested that turning movement restrictions be evaluated at the intersections of North 7th Avenue with Aspen Street and Juniper Street. Initially, it was assumed that 3/4 access would be implemented at the Aspen Street intersection, prohibiting eastbound (EB) and westbound (WB) site egress left-turn and thru movements but maintaining access for northbound (NB) and southbound (SB) site ingress left-turns. With access restricted at Aspen Street, all trips from the 8 Aspen site with destinations to the north (EB left turns) were shifted to the Juniper Street intersection. This resulted in worsened delay at Juniper Street; therefore, several scenarios were evaluated assuming that varying percentages of the NB destination trips would be shifted from site egress EB left-turns and instead be made via a site egress EB right-turn followed by a U-turn at the Tamarack Street intersection, or other alternate routes. WB existing left-turns at the Aspen Street intersection were assumed to shift to either Tamarack Street or Peach Street. The results of this analysis for each of the Full Buildout (2026) and Future (2038) scenarios are described in the following paragraphs and capacity tables are attached. Full Buildout (2026) Analysis In the Full Buildout (2026) scenario with 3/4 access at the Aspen Street intersection and all site egress EB left turns shifted to Juniper Street, minor approach delay at the North 7th Avenue/Aspen Street intersection is projected to improve to LOS B. At the North 7th Avenue/Juniper Street intersection, minor approach delay is projected to reach LOS F, with values double the original analysis presented in the TIS. With 50 percent of the new site egress EB left-turns shifted to EB right-turns/U-turns, the minor approach delay is projected to be cut in half (LOS E), similar to the original analysis. With 75 percent of site egress EB left-turns switched to EB right-turn/U-turn, delay is projected to improve to LOS D. With a 3/4 access restriction at Juniper Street where all site egress EB left-turns are converted to right-turns/U-turns, the minor approaches would operate at LOS B. However, this configuration may not be feasible due to the existing semi-trucks usage on Juniper Street from the Darigold Bozeman factory. Kyle Scarr, PE March 8, 2024 Page 2 A sensitivity analysis was performed to evaluate the number of site egress EB left turns that can be added back into the Juniper intersection before reaching each LOS threshold. It was determined 8/6 (AM Peak Hour/PM Peak Hour) vehicles could execute a site egress EB left turn at Juniper Street with the approach remaining in the LOS D threshold. These values increase to 14/10 and 20/14 for LOS E and LOS F thresholds, respectively. This equates to approximately 63 percent of desired EB left turns in the AM peak hour and 54 percent of desired EB left turns in the PM peak hour that could be made before reaching LOS F on the approach. Future (2038) Analysis In the Future (2038) scenario, shifting all site egress EB left turns from Aspen Street to Juniper Street would nearly triple the minor approach delay projected at Juniper Street in the original TIS, which was already at LOS F prior to shifting volumes. With 3/4 access at Aspen Street, the minor approaches are projected to operate at LOS C or better in the Future (2038) scenario. With 50 percent of site egress EB left turns at Juniper Street shifted to EB right-turns/U-turns, minor approach delay at Juniper Street was projected to improve to similar values from the original TIS. With 75 percent of site egress EB left-turns shifted to EB right-turns/U-turns, minor approach delay values are projected to be reduced by 50 percent, but remain at LOS F. With 3/4 access implemented at Juniper Street and all site egress EB left-turns converted to EB right-turns, the minor approaches of Juniper Street are projected to improve to LOS C or better. Again, a sensitivity analysis was performed to evaluate the number of site egress EB left turns that can be added back into the Juniper intersection before reaching each LOS threshold. It was determined 3/2 (AM Peak Hour/PM Peak Hour) vehicles could execute a site egress EB left turn at Juniper Street with the approach remaining in the LOS D threshold. These values increase to 6/4 and 9/6 for the LOS E and LOS F thresholds, respectively. This equates to approximately 28 percent of desired EB left turns in the AM peak hour and 23 percent of desired EB left turns in the PM peak hour that could be made before reaching LOS F on the approach. Conclusions Although capacity results can be improved at both intersections by restricting access from the minor approaches, this is likely not a preferred condition at Juniper Street due to the increase in U-turn movements that would result, which truck traffic associated with the Darigold factory would not be able to perform inside the current roadway section. Access restrictions at either Aspen Street or Juniper Street are both likely to result in increased U-turn movements on North 7th Avenue. Pedestrian Access Comments received from the City of Bozeman also requested analysis of implementation of a pedestrian crosswalk with flashing lights across North 7th Avenue at Aspen Street. The MDT pedestrian crossing treatment selection matrix and MUTCD pedestrian hybrid beacon (PHB), also commonly known as a High intensity Activated crossWa lK (HAWK), guidelines were therefore evaluated. Kyle Scarr, PE March 8, 2024 Page 3 MDT Guidelines For a crosswalk across a five-lane facility with a speed limit of 35-mph and ADT greater than 17,000, the MDT matrix recommends consideration of an A-level treatment, which could include pedestrian-actuated beacons or a pedestrian signal. Both rectangular rapid flashing beacons (RRFBs) and HAWKs are considered pedestrian-actuated beacons. If a median refuge were provided at this location, the current ADT would still warrant A-level treatment. The MDT matrix is intended to be applied after following a flow-chart which includes a provision that a treatment should be selected if pedestrian volumes meet a minimum of 20 pedestrians per hour for speed limits at or under 35-mph. However, it is also noted that consideration may be given for latent demand, where crossings would occur if an appropriate crossing were present, and that the limits may be reduced based on engineering judgment. For mid-block crossings, the flow-chart recommends 300-foot spacing from the nearest marked or controlled crossing but notes that this distance is approximate and may be reduced based on engineering judgment or where the crossing is on the path of a larger activity generator. MUTCD Guidelines MUTCD HAWK guidelines show that at least 20 pedestrians crossing the major street per hour would be required to warrant a HAWK with existing geometry and volumes. This value would increase if a median refuge were to be provided, thereby reducing the crosswalk length and the major street conflicting vehicle volume. Approximately 50 pedestrians in one hour would be required to warrant a HAWK in the Future (2038) year if a median refuge were provided based on the MUTCD guidelines. If a HAWK was installed, it would have to be coordinated with the nearby signal at Tamarack Street, which may induce additional delay through the North 7th Avenue corridor and would also result in pedestrian delay while waiting for the appropriate time in the corridor cycle to stop mainline vehicle traffic. The on-demand nature of pedestrian-actuated signals could result in impatient pedestrians engaging in riskier decision making while waiting for the signal to turn. MUTCD standards for installation of RRFBs have not been developed, but the City of Boulder, CO Pedestrian Crossing Treatment Guidelines document, published in November 2011, provides a minimum pedestrian crossing value of 20 pedestrians per hour as guidance for RRFB installation. Existing Conditions Although there is not currently a striped crosswalk across North 7th Avenue at Aspen Street, some pedestrian activity was recorded at the intersection. It was found that the highest hour of 11:30 PM to 12:30 AM saw a maximum of 10 pedestrians cross the south leg of North 7th Avenue at this intersection. It was observed that all 10 pedestrians had origins or destinations at the Cat’s Paw bar. Conclusions It is likely that pedestrians desiring to cross North 7th Avenue will become more prevalent upon construction of the proposed 8 Aspen site, as several restaurants and other destinations are located on the east side of North 7th Avenue. A signalized pedestrian crossing is currently present at the North 7th Avenue/Tamarack Street intersection, located approximately 300-feet north of Aspen Street. However, the proposed 8 Aspen site does not provide direct access to Tamarack Street without first accessing either the Juniper Street or Aspen Street intersections with North 7th Avenue. It is unlikely that all pedestrians would walk a total of 600-feet out of their way to utilize the Kyle Scarr, PE March 8, 2024 Page 4 Tamarack Street crossing, creating a potentially dangerous situation if a crosswalk is not provided at Aspen Street. A striped crosswalk with RRFBs should be considered for installation at this intersection, as it would introduce less delay to North 7th Avenue than a HAWK and would not require problematic coordination with the Tamarack Street signal. Although most existing pedestrian crossings across North 7th Avenue were on the south leg, it is recommended that if an RRFB crosswalk is installed, it should be across the north leg of the North 7th Avenue/Aspen Street intersection due to the location of the 8 Aspen Development, developed locations on the east side of North 7th Avenue, and the projected left-turn traffic volumes from North 7th Avenue being lower for SB movements compared to NB movements. If you have any questions or concerns, please feel free to contact me at 406-922-4326 or astoltzfus@sandersonstewart.com. Sincerely, Audrey Stoltzfus, PE, RSP1 Project Engineer ARS/jhs/SG Enc: Capacity tables P:\23505_8_Aspen_Bozeman_TIS_3.8.2024 Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) EB 47.3E1 53.2F1 EB 43.5E2 47.7E2 EB 13.6B1 12.5B1WB13.8B1 16.5C1 WB 14.1B1 16.6C1 WB 10.5B1 14.3B1 NB 0.2A0 0.0A0 NB 0.2A0 0.0A0 NB 0.2A0 0.0A0 SB 0.3A1 0.3A1 SB 0.3A1 0.3A1 SB 0.3A1 0.3A1 Intersection 0.8A --0.9A --Intersection 1.4A --1.3A --Intersection 0.7A --0.6A -- EB 29.5D2 52.5F3 EB 12.9B1 12.6B1 EB 12.9B1 12.6B1 WB 10.3B0 54.0F2 WB 10.3B0 13.3B1 WB 10.3B0 13.3B1 NB 0.4A1 0.9A1 NB 0.4A1 0.9A1 NB 0.4A1 0.9A1SB0.1A0 0.2A1 SB 0.1A0 0.2A1 SB 0.1A0 0.2A1Intersection1.6A --2.8A --Intersection 0.6A --1.0A --Intersection 0.6A --1.0A --FULL ACCESS ANALYSIS 3/4 ACCESS WITH ALL EB LEFTS SHIFTED TO JUNIPER, 50% RT/U-turn/reroute 3/4 ACCESS AT BOTH - ALL EB LEFTS SHIFTED TO JUNIPER, 100% RT/U-turn/reroute Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) EB 89.5F3 110.7F3 EB 27.6D1 28.9D1WB13.9B1 16.5C1 WB 14.2B1 16.6C1NB0.2A0 0.0A0 NB 0.2A0 0.0A0 SB 0.3A1 0.3A1 SB 0.3A1 0.3A1 Intersection 2.4A --2.3A --Intersection 1.1A --0.9A -- EB 12.9B1 12.6B1 EB 12.9B1 12.6B1 WB 10.3B0 13.3B1 WB 10.3B0 13.3B1 NB 0.4A1 0.9A1 NB 0.4A1 0.9A1 SB 0.1A0 0.2A1 SB 0.1A0 0.2A1Intersection0.6A --1.0A --Intersection 0.6A --1.0A --3/4 ACCESS WITH ALL EB LEFTS SHIFTED TO JUNIPER - WB would go to Tamarack/Peach 3/4 ACCESS WITH ALL EB LEFTS SHIFTED TO JUNIPER, 75% RT/U-turn/reroute North 7th Avenue & West Aspen Street Intersection Approach Full Buildout (2026) AM Peak PM Peak Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Aspen Street Intersection Control Two-Way Stop-Control (EB/WB), Full Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Aspen Street Intersection Approach Full Buildout (2026) AM Peak PM Peak Intersection Control Two-Way Stop-Control (EB/WB), Full Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access Intersection Approach Full Buildout (2026) AM Peak PM Peak North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Aspen Street North 7th Avenue & West Aspen Street Intersection Control Two-Way Stop-Control (EB/WB), Full Access Intersection Approach Full Buildout (2026) AM Peak PM Peak Intersection Control Two-Way Stop-Control (EB/WB), Full Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), Full Access Intersection Approach Full Buildout (2026) AM Peak PM Peak Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) EB 98.3F1 154.1F2 EB 104.8F3 147.4F3 EB 16.0C1 14.3B1WB17.6C1 23.3C1 WB 18.1C1 23.3C1 WB 11.2B1 17.4C1 NB 0.2A1 0.0A0 NB 0.2A1 0.0A0 NB 0.2A1 0.0A0 SB 0.3A1 0.3A1 SB 0.3A1 0.3A1 SB 0.3A1 0.3A1 Intersection 1.1A --1.7A --Intersection 2.3A --2.5A --Intersection 0.6A --0.6A -- EB 63.2F3 208.1F5 EB 14.8B1 14.5B1 EB 14.8B1 14.5B1 WB 11.0B0 237.4F4 WB 11.0B0 15.8C1 WB 11.0B0 15.8C1 NB 0.4A1 0.9A1 NB 0.4A1 0.9A1 NB 0.4A1 0.9A1SB0.1A0 0.3A1 SB 0.1A0 0.3A1 SB 0.1A0 0.3A1Intersection2.6A --8.6A --Intersection 0.6A --1.0A --Intersection 0.6A --1.0A --FULL ACCESS ANALYSIS 3/4 ACCESS WITH ALL EB LEFTS SHIFTED TO JUNIPER, 50% RT/U-turn/reroute 3/4 ACCESS AT BOTH - ALL EB LEFTS SHIFTED TO JUNIPER, 100% RT/U-turn/reroute Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) EB 282.9F4 436.6F5 EB 51.7F2 64.8F2WB17.7C1 23.1C1 WB 18.3C1 23.4C1 NB 0.2A1 0.0A0 NB 0.2A1 0.0A0 SB 0.3A1 0.3A1 SB 0.3A1 0.3A1 Intersection 5.4A --6.4A --Intersection 1.3A --1.4A -- EB 14.8B1 14.5B1 EB 14.8B1 14.5B1 WB 11.0B0 15.8C1 WB 11.0B0 15.8C1 NB 0.4A1 0.9A1 NB 0.4A1 0.9A1SB0.1A0 0.3A1 SB 0.1A0 0.3A1Intersection0.6A --1.0A --Intersection 0.6A --1.0A --3/4 ACCESS WITH ALL EB LEFTS SHIFTED TO JUNIPER - WB would go to Tamarack/Peach 3/4 ACCESS WITH ALL EB LEFTS SHIFTED TO JUNIPER, 75% RT/U-turn/reroute North 7th Avenue & West Aspen Street Intersection Approach Future (2038) AM Peak PM Peak Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Aspen Street Intersection Control Two-Way Stop-Control (EB/WB), Full Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Aspen Street Intersection Approach Future (2038) AM Peak PM Peak Intersection Control Two-Way Stop-Control (EB/WB), Full Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access Intersection Approach Future (2038) AM Peak PM Peak Two-Way Stop-Control (EB/WB), Full Access North 7th Avenue & West Juniper Street Intersection Control Two-Way Stop-Control (EB/WB), 3/4 Access North 7th Avenue & West Aspen Street Intersection Control North 7th Avenue & West Aspen Street Intersection Approach Future (2038) AM Peak PM Peak North 7th Avenue & West Juniper Street Two-Way Stop-Control (EB/WB), Full AccessIntersection Control Intersection Control Two-Way Stop-Control (EB/WB), Full Access Intersection Approach Future (2038) AM Peak PM Peak