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HomeMy WebLinkAboutAppendix U.1 - Traffic Impact Study Addendum 03-24-2021 130 South Howie Street Helena, Montana 59601 406-459-1443 March 23, 2021 Matt Hausauer, P.E. Bridger Land Group 115 W. Kagy Blvd, Suite L Bozeman, MT 59715 RE: Blackwood Groves TIS Addendum Dear Matt, Based on review comments from the City of Bozeman, ATS has develop the following addendum to the January 2021 TIS prepared for the Blackwood Groves development. The City has requested additional information regarding any specific traffic impacts from the project by phase and an additional traffic analysis of Goldenstein Lane. The phasing plan and trip generation for the Blackwood Groves development is shown below in Table 1. Table 1 – Blackwood Groves Phasing Plan Single-Family Multi-Family Commercial Office General Commercial Trip Generation dwelling units dwelling units KSF KSF Trips Per Day Phase 1 132 1,246 Phase 2 222 1,208 Phase 3 19 90 669 Phase 4 87 14 897 Phase 5 21 14 274 Phase 6 84 150 155 7,969 Phase 7 154 838 Phase 8 30 283 TOTAL 289 578 150 155 13,384 The phasing plan shows that the overall trip generation for the project will be relatively low until the commercial portion of the project is developed with Phase 6. The current development plan includes the creation of a right in/out only approach onto South 19th Avenue with Phase 1 of the development along with the 11th Avenue and Cambridge Drive connections. Phase 2 will include the construction of a large section of Blackwood Road along with a new connection with 19th Avenue. Phase 2 is planned to be constructed concurrently with Phase 1 which would connect Phase 1 to 19th via Blackwood Road and eliminate the need for the Street B right in/out approach. 19th Avenue will also be widened with Phase 2 to include a five-lane cross-section with turning lanes. The majority of the internal road network would be completed by the end of Phase 3 of the Blackwood Groves development and the final connection to 19th Avenue will be made with Phase 4 (Street E). The Blackwood Groves phasing plan is included with this addendum. 2 Phase 1 of the development would include 132 single-family residential units and would connect to 11th Avenue to the north and Cambridge Drive to the east. The right-in/out approach at 19th Avenue would be beneficial for the overall traffic flow through the property, but ultimately would not be used heavily except for some traffic leaving the development during the morning peak hours. This configuration would force most traffic from Phase 1 (90%) through the roundabout at Graf Street and 11th Avenue. The traffic impacts from Phase 1 would be relatively minor. Traffic volumes at the intersection of Graf Street and 11th Avenue would increase by 14% and the total delay at the roundabout would increase by less than one second per vehicle. By Phase 2 the primary connection to 19th Avenue at Blackwood Road will be developed which will improve traffic flow patterns through the development during construction of the remaining phases of the project. Initially the connection will decrease traffic flows through the 11th/Graf intersection by drawing up to 50% of the development traffic directly onto South 19th Avenue. The first five phases of the development will create 4,295 daily trips to the area (32% of the total trip generation for the project) but will develop the majority of road network within the project. The proposed northern approach to the development and the Blackwood Road connection to south 19th Avenue will function at LOS C at full development. The far southern approach to the project, which would be developed with Phase 4 of the project, was not included in the modeling for the project and all traffic from the Street E connection was funneled to Blackwood Avenue to provide a more conservative result and account for possible access restrictions at that location. Ultimately the Blackwood Road intersection will function at LOS C at full buildout of the development and will not warrant a higher form of traffic control based on the projected traffic patterns along South 19th Avenue. Phases 2-7 of the development will incrementally increase traffic volumes at the Blackwood Road/19th Avenue approach, but no special interim traffic controls would be necessary. Blackwood Road should be developed with two westbound lanes at the 19th Avenue approach to provide sufficient room for possible intersection widening at this location in the future when development continues along Blackwood Road west of 19th Avenue. Depending on the available road spacing between Blackwood Road and Street E and the design speed on 19th Avenue, it may be necessary to restrict left-turn incoming movements at the Street E approach. The City also requested that the intersection of South 3rd Avenue and Goldenstein Lane be analyzed as part of the traffic impact study. Traffic data for this intersection was collected on March 22, 2021 to provide current and future projected LOS for this location. The LOS for existing a full-build traffic is shown in Tables 2 & 3. The analysis indicates that this intersection is currently operating at LOS B/A during the morning and evening peak hours. Traffic from the Blackwood Groves development will account for an 5-10% percent increase in traffic volumes at full buildout and an increase in vehicle delay of 1-3 seconds per vehicle at full buildout of the project. No 3 improvements are recommended for the South 3rd Avenue/Goldenstein Lane intersection at this time. Table 2 – Existing 2020 Level of Service Summary AM Peak Hour PM Peak Hour Intersection Delay (Sec.) LOS Delay (Sec.) LOS 19th Avenue & Graf Street 15.5 B 13.1 B Kagy Boulevard & 11th Avenue 17.1 B 21.3 C Graf Street & 11th Avenue 4.1 A 4.3 A Graf Street & S 3rd Avenue 4.1 A 3.8 A Goldenstein Ln. & S 3rd Ave.* 13.3 B 9.6 A *Based on Traffic data collected 3-22-21 Table 3 –Projected Level of Service Summary AM Peak Hour PM Peak Hour Intersection Delay (Sec.) LOS Delay (Sec.) LOS 19th Avenue & Graf Street 20.6 C 15.6 B Kagy Boulevard & 11th Avenue 22.8 C 32.6 C Graf Street & 11th Avenue 5.1 A 6.3 A Graf Street & S 3rd Avenue 4.7 A 4.5 A 19th Avenue & Mid Approach 14.6 B 17.7 C 19th Avenue & Blackwood 21.3/14.3 C/B 24.1/17.6 C/C S 3rd Avenue & Cambridge Dr. 16.2 C 11.4 B Goldenstein Ln. & S 3rd Ave.* 16.4 C 9.9 A If you have any additional questions regarding the TIS for the Blackwood Groves development, please feel free to contact me at 406-459-1443. Sincerely, Bob Abelin, P.E. PTOE Abelin Traffic Services, Inc. HCS7 Two-Way Stop-Control Report General Information Site Information Analyst RLA Intersection Goldenstein & 3rd Agency/Co.ATS Jurisdiction City of Bozeman Date Performed 3/19/2021 East/West Street Goldenstein Lane Analysis Year 2021 North/South Street 3rd Street Time Analyzed AM Peak Hour Peak Hour Factor 1.00 Intersection Orientation East-West Analysis Time Period (hrs)0.25 Project Description Blackwood Groves Lanes Major Street: East-West Vehicle Volumes and Adjustments Approach Eastbound Westbound Northbound Southbound Movement U L T R U L T R U L T R U L T R Priority 1U 1 2 3 4U 4 5 6 7 8 9 10 11 12 Number of Lanes 0 0 1 0 0 0 1 0 0 0 0 0 1 0 Configuration LT TR LR Volume (veh/h)196 28 160 140 48 108 Percent Heavy Vehicles (%)3 3 3 Proportion Time Blocked Percent Grade (%)0 Right Turn Channelized Median Type | Storage Undivided Critical and Follow-up Headways Base Critical Headway (sec)4.1 7.1 6.2 Critical Headway (sec)4.13 6.43 6.23 Base Follow-Up Headway (sec)2.2 3.5 3.3 Follow-Up Headway (sec)2.23 3.53 3.33 Delay, Queue Length, and Level of Service Flow Rate, v (veh/h)196 156 Capacity, c (veh/h)1255 587 v/c Ratio 0.16 0.27 95% Queue Length, Q₉₅ (veh)0.6 1.1 Control Delay (s/veh)8.4 13.3 Level of Service (LOS)A B Approach Delay (s/veh)7.5 13.3 Approach LOS B Copyright © 2021 University of Florida. All Rights Reserved. HCS™TWSC Version 7.8.5 Generated: 3/24/2021 8:46:51 AMGoldensteinAM.xtw HCS7 Two-Way Stop-Control Report General Information Site Information Analyst RLA Intersection Goldenstein & 3rd Agency/Co.ATS Jurisdiction City of Bozeman Date Performed 3/19/2021 East/West Street Goldenstein Lane Analysis Year 2021 North/South Street 3rd Street Time Analyzed PM Peak Hour Peak Hour Factor 1.00 Intersection Orientation East-West Analysis Time Period (hrs)0.25 Project Description Blackwood Groves Lanes Major Street: East-West Vehicle Volumes and Adjustments Approach Eastbound Westbound Northbound Southbound Movement U L T R U L T R U L T R U L T R Priority 1U 1 2 3 4U 4 5 6 7 8 9 10 11 12 Number of Lanes 0 0 1 0 0 0 1 0 0 0 0 0 1 0 Configuration LT TR LR Volume (veh/h)56 64 64 12 32 52 Percent Heavy Vehicles (%)3 3 3 Proportion Time Blocked Percent Grade (%)0 Right Turn Channelized Median Type | Storage Undivided Critical and Follow-up Headways Base Critical Headway (sec)4.1 7.1 6.2 Critical Headway (sec)4.13 6.43 6.23 Base Follow-Up Headway (sec)2.2 3.5 3.3 Follow-Up Headway (sec)2.23 3.53 3.33 Delay, Queue Length, and Level of Service Flow Rate, v (veh/h)56 84 Capacity, c (veh/h)1517 862 v/c Ratio 0.04 0.10 95% Queue Length, Q₉₅ (veh)0.1 0.3 Control Delay (s/veh)7.5 9.6 Level of Service (LOS)A A Approach Delay (s/veh)3.6 9.6 Approach LOS A Copyright © 2021 University of Florida. All Rights Reserved. HCS™TWSC Version 7.8.5 Generated: 3/24/2021 8:47:22 AMGoldensteinPM.xtw HCS7 Two-Way Stop-Control Report General Information Site Information Analyst RLA Intersection Goldenstein & 3rd Agency/Co.ATS Jurisdiction City of Bozeman Date Performed 3/19/2021 East/West Street Goldenstein Lane Analysis Year 2025 North/South Street 3rd Street Time Analyzed AM Peak With Dev.Peak Hour Factor 1.00 Intersection Orientation East-West Analysis Time Period (hrs)0.25 Project Description Blackwood Groves Lanes Major Street: East-West Vehicle Volumes and Adjustments Approach Eastbound Westbound Northbound Southbound Movement U L T R U L T R U L T R U L T R Priority 1U 1 2 3 4U 4 5 6 7 8 9 10 11 12 Number of Lanes 0 0 1 0 0 0 1 0 0 0 0 0 1 0 Configuration LT TR LR Volume (veh/h)225 32 184 173 67 124 Percent Heavy Vehicles (%)3 3 3 Proportion Time Blocked Percent Grade (%)0 Right Turn Channelized Median Type | Storage Undivided Critical and Follow-up Headways Base Critical Headway (sec)4.1 7.1 6.2 Critical Headway (sec)4.13 6.43 6.23 Base Follow-Up Headway (sec)2.2 3.5 3.3 Follow-Up Headway (sec)2.23 3.53 3.33 Delay, Queue Length, and Level of Service Flow Rate, v (veh/h)225 191 Capacity, c (veh/h)1196 500 v/c Ratio 0.19 0.38 95% Queue Length, Q₉₅ (veh)0.7 1.8 Control Delay (s/veh)8.7 16.6 Level of Service (LOS)A C Approach Delay (s/veh)7.8 16.6 Approach LOS C Copyright © 2021 University of Florida. All Rights Reserved. HCS™TWSC Version 7.8.5 Generated: 3/24/2021 8:47:41 AMGoldensteinAMwith.xtw HCS7 Two-Way Stop-Control Report General Information Site Information Analyst RLA Intersection Goldenstein & 3rd Agency/Co.ATS Jurisdiction City of Bozeman Date Performed 3/19/2021 East/West Street Goldenstein Lane Analysis Year 2025 North/South Street 3rd Street Time Analyzed PM Peak With Dev.Peak Hour Factor 1.00 Intersection Orientation East-West Analysis Time Period (hrs)0.25 Project Description Blackwood Groves Lanes Major Street: East-West Vehicle Volumes and Adjustments Approach Eastbound Westbound Northbound Southbound Movement U L T R U L T R U L T R U L T R Priority 1U 1 2 3 4U 4 5 6 7 8 9 10 11 12 Number of Lanes 0 0 1 0 0 0 1 0 0 0 0 0 1 0 Configuration LT TR LR Volume (veh/h)64 74 74 33 37 79 Percent Heavy Vehicles (%)3 3 3 Proportion Time Blocked Percent Grade (%)0 Right Turn Channelized Median Type | Storage Undivided Critical and Follow-up Headways Base Critical Headway (sec)4.1 7.1 6.2 Critical Headway (sec)4.13 6.43 6.23 Base Follow-Up Headway (sec)2.2 3.5 3.3 Follow-Up Headway (sec)2.23 3.53 3.33 Delay, Queue Length, and Level of Service Flow Rate, v (veh/h)64 116 Capacity, c (veh/h)1478 843 v/c Ratio 0.04 0.14 95% Queue Length, Q₉₅ (veh)0.1 0.5 Control Delay (s/veh)7.5 9.9 Level of Service (LOS)A A Approach Delay (s/veh)3.7 9.9 Approach LOS A Copyright © 2021 University of Florida. All Rights Reserved. HCS™TWSC Version 7.8.5 Generated: 3/24/2021 8:48:02 AMGoldensteinPMwith.xtw