HomeMy WebLinkAbout25.1 Traffic Calming Addendum MEMORANDUM To: Mr. Andrew Gault, Homebase Partners From: Joey Staszcuk, PE, PTOE, RSP1, Senior Traffic Engineer Date: 4/29/2024 Reference: 23509, The Guthrie – Bozeman TIS addendum #2 The purpose of this memo is to provide an addendum to The Guthrie traffic impact study (TIS) to meet the requests set forth by the City of Bozeman. Local street evaluation of impacts were requested based on existing and proposed future daily volumes of the Guthrie Development. As noted in The Guthrie TIS, November 2023, traffic data was collected on Thursday, November 2, 2023. Daily traffic volumes (ADTs) were monitored and found to be on 5th Avenue from 450 to 500 daily vehicles, along Villard Street from 600 to 750 daily vehicles, and along Beall Street from 500 to 550 daily vehicles. The 438 proposed daily new external Guthrie vehicle trips were then applied to the network based on the TIS distribution. Finally, a 2-percent ambient background growth for 15-years was added to the volumes to develop the Design Year (2038) Traffic Projections. Daily traffic volumes are estimated in 2038 to be 710 – 1050 daily vehicles on 5th Avenue, 830 – 1150 daily vehicles on Villard Street, and 690 – 860 daily vehicles on Beall Street. The 2017 Bozeman Transportation Master Plan notes the Theoretical Roadway Capacity of a 2-lane roadway to be 12,000 daily vehicles. Reaching the capacity of a roadway section would best be defined as complete gridlock. Attached Figure 4 & Figure 6 describe the existing and Design Year traffic volumes. The Guthrie development is in an area of town that is comprised of almost entirely a local street network. Two blocks west of The Guthrie, 7th Avenue is a north/south orientated Principal Arterial and nine blocks to the east is Rouse Avenue, which is also a north/south orientated Principal Arterial. Three blocks south of the Guthrie, Mendenhall Street is a westbound-only Minor Arterial and another block to the south is Main Street, which is an east/west orientated Principal Arterial. Finally, three blocks north of the Guthrie is Peach Street, which is an east/west orientated Collector. Inside the boundary of these elevated roadways, is 0.25 square-miles of local road networks that are often used as routes to the downtown businesses. The east/west orientated routes are generally free flowing (no stop or yield control) with the north/south orientated routes having stop or yield control. There are a few exceptions to the eastern side of this boundary with fully uncontrolled intersections, stop control on the east/west orientated routes and a few traffic calming measures. All local streets are 25-mph which the exception of roads adjacent to schools (5th Avenue) and parks that are 15-mph.
April 29, 2024 2 From the described local roadway network, anecdotal information suggests that the east/west routes may influence higher traffic volumes and elevated vehicle speeds due to the free-flowing operations and Mendenhall Street being restricted to westbound only. Villard Street and Beall Street would be the two Guthrie adjacent east/west routes. Due to the mainly residential development in the prior described local roadway boundary and the trip destination locations of schools, parks, and downtown businesses nearby, local streets in the area experience high multi-modal volumes. The Guthrie development will also generate an increase of multi-modal trips based on the development plan. When local streets experience greater than 1000 ADT, traffic calming measures should be considered to regulate vehicle traffic speeds and to ensure pedestrian safety. The Federal Highway Administration (FHWA) Traffic Calming ePrimer provides a toolbox of traffic calming measures to consider based on roadway characteristics, desired outcomes, and sustainability. These traffic calming measures should be reviewed for the appropriate application based on several factors including speed limits, traffic volumes, emergency routes, transit, maintenance, grade, etc. Based on the local characteristics and the challenge of both reducing vehicle speeds and providing safe pedestrian facilities, a traffic circle should be considered at the 5th Avenue and Villard Street intersection based on the FHWA toolbox. This recommended improvement should be designed to allow mountable outer curb with a raised inner circle and designed to accommodate local traffic, school buses, City maintenance vehicles, and firetrucks. This traffic calming alternative will assist with reducing existing vehicle travel speeds and will maintain safety for pedestrians that are already on the network, as well as assist with future Guthrie trip generation and the surrounding growth. If you have any questions or concerns, please feel free to contact me at 406-922-4306 or jstaszcuk@sandersonstewart.com.
April 29, 2024 3 Figure 4: Existing Conditions (2023) Traffic Volumes (Updated 1/26/2024)
April 29, 2024 4 Figure 6: Design Year (2038) Traffic Projections (Updated 1/26/2024)