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HomeMy WebLinkAbout2-3 Traffic Departure Reportmemo Page 1 TO: City of Bozeman Engineering FROM: Toby McClue, PE; Wyatt Hatch, PE DATE: February 17, 2023 JOB NO.: 10093.001 RE: 2695 Tschache Lane Roadway Tangent Departure Request CC: Matt Booma, File Urgent For Review Please Comment Please Reply For Your Use This memorandum provides additional information as required by Bozeman Municipal Code (BMC) Section 38.400.090.H for request for departure from Distance from Intersections and Tangent Road Lengths. Roadway extensions are required for the proposed 2695 Tschache Lane Development Project. Design and alignment of these roadways considered City of Bozeman Design Standards. Proposed North 25th Avenue and Turbulence Lane are considered local streets. BMC 38.400.090-1 Distance from Intersections Design of the proposed development considered placement of accesses off the proposed local roads based on BMC Table 38.400.090-1. All requirements are met with exception of the existing driveway access to the Baxter Apartments off Trade Wind Lane. The distance of the existing driveway to North 25th Avenue is 36.3 feet, which is less than the required 40-feet. This minimum requirement is unable to be met due to the existing alignment of the property line (right-of-way) and the existing roadway approach located on the northside of Baxter Lane. Proposed roadway is based on design of a local road per City of Bozeman including 5-ft wide sidewalk, 6.5-ft wide boulevard and 35-foot wide roadway with parallel parking. Traffic Volumes Based on data from the Traffic Impact Study (TIS) completed in 2022 by E5 Engineering, PLLC estimated traffic volume at the intersection of North 25th Avenue and Trade Wind Lane is minimal. The table below summarizes the estimate traffic volumes for this intersection from the proposed development and 2027 projections. 2695 Tschache Lane Roadway Tangent Departure Request Page 2 Turning Movements The existing driveway access off Trade Wind Lane allow right and left turn movements out of the Baxter Apartments onto Trade Wind Lane. Access into the Baxter Apartments off Trade Wind Lane heading west allow a right turn and straight movement. Access into the Baxter Apartments off Trade Wind Lane heading east allow a left turn and straight movement. The proposed roadway intersection of Trade Wind Lane and North 25th Avenue allow for right and left turn movements off of Trade Wind Lane onto North 25th Avenue. Access onto Trade Wind Lane from North 25th Avenue heading north allow a left turn and straight movement. Access onto Trade Wind Lane from North 25th Avenue heading south allow a right turn and straight movement. Traffic Controls The subject property is currently undeveloped land with no existing roadways. The existing driveway off Trade Wind Lane utilizes a stop sign to control traffic exiting the Baxter Apartments. Upon completion of development and construction of North 25th Avenue, the intersection of North 25th Avenue and Trade Wind Lane will be controlled with a stop sign controlling traffic movement onto North 25th Avenue. Site Design The proposed alignment of North 25th Avenue was designed based on existing property boundaries (right-of-way) and existing access approach located on the north side of Baxter Lane. The 40-foot minimum requirement is unable to be met based on previously approved location of existing driveway access into the Baxter Apartments. Sight Distances Sight distances for the existing driveway and proposed intersection of North 25th Avenue and Trade Wind Lane are designed to optimize sight distances. Vision Triangles were designed in Traffic Movement AM PM Trade Wind Lane - Left Turn (N) 10 7 Trade Wind Lane - Right Turn (S) 0 1 North 25th Avenue (N) - Left Turn (W) 2 1 North 25th Avenue (N) - Straight (N) 14 11 North 25th Avenue (S) - Right Turn (W) 4 8 North 25th Avenue (S) - Straight (S) 10 13 North 25th Avenue & Trade Wind Lane 2695 Tschache Lane Roadway Tangent Departure Request Page 3 accordance with BMC Section 38.400.100. No obstructions greater than 3 feet in height are proposed in the design at this location including monument signs and trees. Location and Alignment from other Access Points The location of the proposed North 25th Avenue is described above. The proposed intersection of North 25th Avenue and Trade Wind Lane do not alter the existing alignment of Trade Wind Lane and provide a perpendicular intersection between the two roadways. City of Bozeman Design Standards Section IV.D Roadway design for the proposed development considered City of Bozeman local road standards and City of Bozeman Roadway Design Standards. Tangent length requirements were unable to be met at certain locations within Turbulence Lane and North 25th Avenue. Tangent lengths were reduced to maximize developable area while keeping vehicular and pedestrian safety as a priority. It was the developer’s intent to provide traffic calming movements within the roadways within Turbulence Lane to increase safety at the main intersection of the development (Turbulence Lane and North 25th Avenue). The slight bend within North 25th Avenue was required to adjust roadway alignment to tie-in directly across from the existing access located on the north side of Baxter Lane. The tangent length along Turbulence Lane from North 27th Avenue is 63.2 feet, the tangent length between the reverse curve is 25.5 feet with large radii. The reverse curve tangent length along North 25th Avenue between Turbulence and Trade Wind Lanes is 44.2 feet. Traffic Volumes Based on data from the Traffic Impact Study (TIS) completed in 2022 by E5 Engineering, PLLC estimated traffic volume on North 25th Avenue and Turbulence Lane are anticipated to be minimal. The tables below summarize the anticipated traffic volumes from the proposed development and 2027 projections. Traffic Intersection AM PM North 25th Avenue & Turbulence Lane (N) 8 16 North 25th Avenue & Turbulence Lane (S) 16 16 North 25th Avenue & Trade Wind Lane (N) 16 12 North 25th Avenue & Trade Wind Lane (S) 14 21 North 25th Avenue Traffic 2695 Tschache Lane Roadway Tangent Departure Request Page 4 Turning Movements Each intersection described in the above tables allow for right turn, left turn and straight traffic movements. The proposed roadways are two-way roads with 10-ft wide drive lanes with speeds limited to local roadway speed designations. There is one access to the north off Turbulence Lane and three accesses to the south off Turbulence Lane. There is one access to the east of North 25th Avenue between the intersection of North 25th Avenue with Turbulence and Trade Wind Lanes. Traffic Controls The subject property is currently undeveloped land with no existing roadways. Traffic controls for North 25th Avenue and Turbulence Lane include local road speed designation and stop signs. A stop sign will be located to control traffic from Turbulence Lane onto North 27th Avenue. A stop sign will be located to control traffic from Trade Wind Lane onto North 25th Avenue. The intersection of North 25th Avenue and Turbulence Lane will be a four-way stop controlled with stop signs. Each driveway approach described above will control access onto the roadways with a stop sign. Site Design The roadway design for Turbulence Lane and North 25th Avenue are based on the proposed site development, zoning setbacks, block frontage classification, local road standards and existing access locations onto North 27th Avenue, Turbulence Lane, Trade Wind Lane, Tschache Lane, Baxter Lane and the Bozeman West Apartments development located directly to the east. The proposed intersection of North 25th Avenue and Turbulence Lane will be the busiest intersection of the development and the use of slight curvature in the Turbulence Lane roadway alignment will help to slow vehicles prior to the intersection and increase vehicular and pedestrian safety. The slight bend in North 25th Avenue will help to slow traffic prior to the North 25th Avenue and Trade Wind Lane intersection to also increase vehicular and pedestrian safety, while maintaining alignment with the existing access located on the north side of Baxter Lane. Traffic Intersection AM PM North 27th Avenue & Turbulence Lane (E) 0 0 North 27th Avenue & Turbulence Lane (W) 23 12 North 25th Avenue & Turbulence Lane (E) 19 11 North 25th Avenue & Turbulence Lane (W) 2 2 Turbulence Lane Traffic 2695 Tschache Lane Roadway Tangent Departure Request Page 5 Sight Distances Sight distances at all proposed roadway and driveway accesses are designed to optimize sight distance. Vision Triangles were designed in accordance with BMC Section 38.400.100. No obstructions greater than 3 feet in height are proposed in the design at this location including monument signs and trees. The design of the roadway alignments with bends are slight to avoid sight distance issues while navigating each roadway due to on-street parallel parking stalls. Line of sight is provided prior to each roadway intersection a minimum of distance of 150 feet. Location and Alignment from other Access Points The proposed roadways are aligned based on existing access points onto the subject property and are aligned with existing roadways surrounding the proposed development. Accesses onto the proposed roadways are designed in accordance with BMC 38.400.090 for local roads.