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Home My WebLink About07 Transportation Impact Summary & Access Relaxation Request 03092021 March 9, 2021 Martin Johnson HRDC Bozeman 32 S Tracy Avenue Bozeman, MT 59715 Reference: Community First Griffin Place (CFGP) – Traffic Analysis 206 E Griffin Drive, Bozeman, MT 59715 Project No. 19078.02 Dear Mr. Johnson: The purpose of this letter is to provide a traffic analysis and justify a deviation request for the HRDC Community First Griffin Place (CFGP) development. This report will utilize a previous traffic study completed to aid the City of Bozeman during the reconstruction of Griffin Drive. Proposed Project This project proposes construction of two buildings on approximately 5.7 acres south of Griffin Drive and east of the railroad crossing. The site location and current site plan are shown in the attached Figure 1. The North Building will include a restaurant, warehousing, food processing, a retail store, and offices. The South Building will include offices, classrooms, conference and meeting rooms, lounges, common areas, as well as short-term living quarters. Site Access Access to the site is proposed via two full-movement approaches to the south of Griffin Drive which will line up with existing approaches to the north. The western access will serve as the primary site access while the eastern access will only be used for service vehicles and staff. Parking Spaces The proposed site plan provides 132 parking spaces, eight (8) of which are designated as ADA- accessible. The City of Bozeman municipal code requires 132 parking spaces for this type and size of development after a 10% reduction for area transit availability adjacent to the site. Therefore, the proposed number of parking spaces is adequate to satisfy the code requirement. Trip Generation Land Use Descriptions This study utilized Trip Generation, 10th Edition, published by the Institute of Transportation Engineers (ITE), which is the most widely accepted source in the United States for determining trip generation projections. The following land use descriptions align with the City of Bozeman parking calculation rates provided by HRDC. · Land Use Code 150 - Warehousing represents the warehouse, food processing, lobbies, and offices accessory to the warehouse. Martin Johnson HRDC Bozeman March 9, 2021 Page 2 · Land Use Code 814 – Variety Store represents the store and bread room. · Land Use Code 710 – General Office represents the office, lobby, and common area in both the north and south buildings. · Land Use Code 932 - High-Turnover (sit-down) Restaurant represents the Fork and Spoon Restaurant and kitchen facilities. · Land Use Code 253 - Congregate Care Facility represents the 170 beds and common area that provides centralized amenities such as dining, housekeeping, and transportation. Trip Generation Table 1 illustrates the results of the trip generation calculations for the site. Table 1: Trip Generation Intensity Units total enter exit total enter exit total enter exit 18.96 1000 Sq. Ft. 33 16 17 3 2 1 4 1 3 3.28 1000 Sq. Ft. 208 104 104 10 6 4 22 11 11 1.78 1000 Sq. Ft. 17 8 9 2 2 0 2 0 2 90 Seats 393 196 197 43 22 21 38 22 16 6.61 1000 Sq. Ft. 64 32 32 8 7 1 8 1 7 170 Dwelling Units 343 171 172 12 7 5 31 16 15 1058 527 531 78 46 32 105 51 54 Units = 1000 SF GFA Average Weekday Average Rate = 1.74 (50% entering, 50% exiting) Peak Hour of the Adjacent Street, One Hour between 7 and 9 AM: Average Rate = 0.17 (77% entering, 23% exiting) Peak Hour of the Adjacent Street, One Hour between 4 and 6 PM: Average Rate = 0.19 (27% entering, 73% exiting) Units = 1000 SF GFA Average Weekday Average Rate = 63.47 (50% entering, 50% exiting) Peak Hour of the Adjacent Street, One Hour between 7 and 9 AM: Average Rate = 3.18 (57% entering, 43% exiting) Peak Hour of the Adjacent Street, One Hour between 4 and 6 PM: Average Rate = 6.84 (52% entering, 48% exiting) Units = 1000 SF GFA Average Weekday Average Rate = 9.74 (50% entering, 50% exiting) Peak Hour of the Adjacent Street, One Hour between 7 and 9 AM: Average Rate = 1.16 (86% entering, 14% exiting) Peak Hour of the Adjacent Street, One Hour between 4 and 6 PM: Average Rate = 1.15 (16% entering, 84% exiting) High-Turnover (Sit-Down) Restaurant - Land Use Code 932* Units = Seats Average Weekday Average Rate = 4.37 (50% entering, 50% exiting) Peak Hour of the Adjacent Street, One Hour between 7 and 9 AM: Average Rate = 0.48 (52% entering, 48% exiting) Peak Hour of the Adjacent Street, One Hour between 4 and 6 PM: Average Rate = 0.42 (57% entering, 43% exiting) Units = Dwelling Units Average Weekday Average Rate = 2.02 (50% entering, 50% exiting) Peak Hour of the Adjacent Street, One Hour between 7 and 9 AM: Average Rate = 0.07 (60% entering, 40% exiting) Peak Hour of the Adjacent Street, One Hour between 4 and 6 PM: Average Rate = 0.18 (53% entering, 47% exiting) *Trip Generation, 10th Edition, Institute of Transportation Engineers, 2017 **Trip Generation Handbook, 3rd Edition, Institute of Transportation Engineers, 2017 Congregate Care Facility - Land Use Code 253* Warehousing - Land Use Code 150* General Office Building - Land Use Code 710* Variety Store - Land Use Code 814* PM Peak Hour Land Use Independent Variable Average Weekday AM Peak Hour North Building South Building General Office Building Total New External Trips Congregate Care Facility High-Turnover (Sit-Down) Restaurant General Office Building Warehousing Variety Store Martin Johnson HRDC Bozeman March 9, 2021 Page 3 The combined land uses are projected to generate a total of 1,058 gross daily trips, 78 AM peak hour trips, and 105 PM peak hour trips. The specific uses of the development will likely see a small percentage of internal capture trips between the restaurant, store/bread room, and overnight housing. Additionally, it is anticipated a high level of patrons of the site will have trips made by alternative modes (walking, biking, transit). For this study, however, all site generated trips were conservatively assumed and modeled as vehicle trips. Intersection Vehicle Trips Vehicle Trips were assigned to the site access intersections using the trip distribution based on the City of Bozeman Griffin Drive corridor analysis. HRDC site trips were combined with the Design Year (2039) Griffin Drive traffic volumes, as shown in the attached Figure 2. The Griffin Drive reconstruction project will provide a westbound left turn lane on Griffin Drive into the HRDC west access and a two-way left-turn lane (TWLTL) adjacent to the HRDC east access. The west HRDC access proposed both a left and right-turn lane for egress movements. The east HRDC access proposes a single lane for all egress movements. LOS Calculations Capacity calculations were performed using Highway Capacity Software (HCS7), which is based on the Highway Capacity Manual, 6th Edition. The results showed that both site accesses are anticipated to operate at LOS C or better during both AM and PM peak hours of the Design Year (2039) with minor queuing. Bozeman Municipal code section 38.400.060 states that all arterial and collector street must operate at minimum level of service C. The results of the capacity analysis are shown in Table 2. Table 2: Design Year Capacity Calculations Pedestrian Connectivity The City of Bozeman Griffin Drive reconstruction project will provide a separated multi-use path on the south side of Griffin Drive adjacent to the HRDC site including ADA compliant crossings at Avg Delay (s/veh) LOS 95th % Queue (veh) Avg Delay (s/veh) LOS 95th % Queue (veh) EB 0.0 A 0 0.0 A 0 WB 0.4 A 1 0.3 A 1 NB - Left 19.7 C 1 21.9 C 1 NB - Right 11.8 B 1 11.5 B 1 EB 0.0 A 0 0.0 A 0 WB 0.1 A 0 0.1 A 0 NB 12.9 B 0 13.0 B 1 Intersection Control One-Way Stop-Control (NB) Intersection Approach Design Year (2039) AM Peak PM Peak East HRDC Access & Griffin Drive West HRDC Access & Griffin Drive Martin Johnson HRDC Bozeman March 9, 2021 Page 4 both site accesses. Internal site sidewalks are proposed to connect to the Griffin Drive path and circulate bicyclists/pedestrian throughout the site to both buildings and all parking lots. Transit bus stops (Streamline) are proposed on both the north and south sides of Griffin Drive adjacent to the HRDC site. Requested Deviation A deviation is requested per the City’s Uniform Development Code (UDC) (38.400.090.H) to permit an approach for the proposed HRDC west access. The approach is closer to the Griffin Drive/Manley Road intersection than the UDC allows based on the City’s classification of Griffin Drive as a minor arterial. The proposed locations of the two HRDC accesses align with the Mergenthaler and Northwestern Energy approach locations. Based on the Design Year (2039) intersection capacity calculations, the 95th percentile queueing will be a maximum of 1 vehicle or less on all legs of the HRDC site access. This amount of queueing will not interfere with the operation of the Griffin Drive and Manley Road intersection. Sight Distance Intersection Sight Distance (ISD) was evaluated at the proposed approach location using criteria from the MDT Traffic Engineering Manual, Chapter 28.9.2 and a 35-mph design speed. A sight distance of 390 feet to the west and 410 feet to the east is required for egress site vehicles. Figure 3 illustrates the calculated sight triangles. It is recommended the placement of the bus stop be located outside of the sight triangles which should be determined in the field during the construction phase. Based on the above analysis, there are no anticipated queueing, vehicular capacity, or sight triangle issues that are impacted by the location of the HRDC Community First Griffin Place site on Griffin Drive. It is recommended that the HRDC site access deviation request be approved. Please feel free to call me at 406-922-4306 if you have any questions or would like to discuss this further. Sincerely, Joey Staszcuk, PE, PTOE Senior Transportation Engineer Community Transportation Studio Manager ARS/jhs Enc. P:19078_02_CFGP_HRDC_Traffic_Analysis_030921