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HomeMy WebLinkAbout006 Nexus Point Phase 2 TIS Update MARVIN & ASSOCIATES 1300 N. Transtech Way Billings, MT 59102 Mailing Address: P.O. Box 80785 Billings, MT 59108-0785 Phone: 406-655-4550 FAX: 406-655-4991 Email: bobm@marvinassociates.com Erik Ringsak, EI Madison Engineering, LLC 895 Technology Blvd, Suite 203 Bozeman, MT 59718 January 23, 2023 Re: Nexus Point Phase 2 Update The City of Bozeman staff requested an evaluation of traffic impacts associated with proposed changes to Phase 2 land uses within the Nexus Point Subdivision. The original Nexus Point/Graf Apartments Traffic Impact Study (TIS) indicated that there would be 120 Mid-Rise apartment units within the Phase 2 development along with 16,000 square feet of office space. Since that time plan changes were made to add 22 apartment units and a 1,900 square foot cafe addition to one of the apartment buildings. The following narratives and attachments summarize our analysis of potential impacts associated with the proposed development additions. Trip Generation The tables on the following page show the trip generation values contained within the original TIS report. The changes and additions shown in red fonts. ITE Trip Generation Code 932 “ High Turnover Restaurant” trip rates were considered appropriate to estimate trip generated associated with the proposed Café. Twenty-two midrise apartment units were added to the original 120 units. In order to determine vehicular trips, trip mode and & classification of trip types were also determined. The percentage of pedestrian and bicycle trips remained the same, while the number of Internal Capture Trips increased due to the trip capture potential of the on-site restaurant. The resultant net vehicular trips are projected to be 1,359 average weekday trips (AWT) with 109 in the peak AM hour and 123 in the peak PM hour. In comparing the total vehicular trips to the original Nexus Point TIS projections, it was determined that the proposed changes in the Phase 2 development would result in an additional 97 AWT with 23 more trips in the peak AM hour and 25 in the peak PM hour. Trip generation characteristics of the restaurant influenced the relative number of trips entering and exiting the subdivision. In the peak AM hour, there would be an additional 11 vehicles entering and 12 exiting, while there would be 16 entering and 9 exiting during the peak PM hour. MARVIN & ASSOCIATES 1300 N. Transtech Way Billings, MT 59102 Mailing Address: P.O. Box 80785 Billings, MT 59108-0785 Phone: 406-655-4550 FAX: 406-655-4991 Email: bobm@marvinassociates.com Distribution & Traffic Assignment The original TIS trip distribution percentages were used in the traffic assignment analysis. It was determined that the vast majority of vehicular traffic would utilize the Arnold Road access to S 19th Avenue. While it is likely that some of the trip could filter through the Graf Apartments development south of Nexus Point to access Graf Street, the number of trips using that route would be fractional. Therefore, all of the additional trips were assigned to the Arnold Street access to S 19th Avenue. Additional traffic volume assignments to external intersection were evaluated and it was determined that the additional traffic would be insignificant in terms of changing the levels-of-service at those intersections. The figure on the following page compares the original traffic volume impacts at the intersection of Arnold Street and S 19th Avenue to the impacts associated with Phase 2 development changes. It is believed that this figure clearly illustrates that the additional traffic is very minor in comparison to the overall development’s traffic volumes. No. of Rate Total Total Total Units Units Rate Trips Rate Trips Enter Exit Rate Trips Enter Exit Phase 1 Code 221 Mid-Rise Apartment 120 Apt. Unit 1 653 2 41 11 30 3 53 32 21 Phase 2 Code 221 Mid-Rise Apartment 142 Apt. Unit 1 772 2 48 10 38 3 62 38 24 Code 710 General Offices 16.0 1,000 S.F.4 179 5 19 16 3 6 10 2 8 Code 932 High Turnover Restaurant 1.9 1,000 S.F.7 208 8 19 10 9 9 18 11 7 1812 127 47 80 143 83 60 1 - T = 5.44(X) 4 - Ln(T) = 0.97Ln(X)+2.50 7 - T = 107.2(X) 181 13 5 8 14 8 6 272 523 633 453 18 7 11 20 11 9 1359 109 40 69 123 72 51 Trip Generation Update for Changes to Nexus Point Phase 2 Subdivision 2 - Ln(T) = 0.98Ln(X)-.98 (26% enter) 5 - T = 1.16(X) (86% enter) 3 - Ln(T) = 0.96Ln(X)-.63 (61% enter) 6 - Ln(T) = 0.95Ln(X)-.36 (16% enter) Pedestrian & Bike Modes 8 - T = 9.57(X) (55% enter0 Total Development Net Vehicular Trips = Peak AM HourAve. Weekday Peak PM Hour Nexus Point Total Potential Trips = Total Trip Mode and Class Reductions = NEXUS POINT SUBDIVISION 9 - T = 9.05(X) (61% enter) Trip Mode & Class Adjustments Internal Capture Within Subdivision MARVIN & ASSOCIATES 1300 N. Transtech Way Billings, MT 59102 Mailing Address: P.O. Box 80785 Billings, MT 59108-0785 Phone: 406-655-4550 FAX: 406-655-4991 Email: bobm@marvinassociates.com Capacity Impacts The table below shows that the LOS for the intersection of Arnold Street & S 19th Avenue would still operate at LOS “C” or better for each critical movement (see attached capacity calculations). Only minor changes in average vehicle delay would occur with no change in the maximum vehicle queues. Delay Max Delay Max Delay Max Delay Max Delay (Sec) LOS Queue (Sec) LOS Queue (Sec) LOS Queue (Sec) LOS Queue (Sec) LOS ORIGINAL TIS S 19TH Avenue & Arnold Street AM 14.3 B 1 8.0 A 0 S 19TH Avenue & Arnold Street PM 17.1 C 1 9.3 A 1 S19th Avenue & Graf Street AM Hour 14.6 B 1 8.0 A 0 S19th Avenue & Graf Street PM Hour 17.5 C 1 9.4 A 1 WITH ADDITIONAL PHASE 2 TRAFFIC Intersection Existing Plus Site Traffic Peak AM & PM Hour Capacity Analysis Comparison EB WB NB SB Intersection MARVIN & ASSOCIATES 1300 N. Transtech Way Billings, MT 59102 Mailing Address: P.O. Box 80785 Billings, MT 59108-0785 Phone: 406-655-4550 FAX: 406-655-4991 Email: bobm@marvinassociates.com For future conditions, the eastbound approach on Arnold Street would operate at LOS “F,” as detailed in the original TIS and the operation of traffic on S 19th Avenue would operate with free-flow movements. Since the Highway Capacity Manual does not have an accepted method to calculate overall LOS for two-way stop intersections, the overall LOS at this intersection in the future is speculated to be LOS “B”, based on the fact that the vast majority of traffic entering the intersection would not be delayed. Addition of an Arnold Street approach from the east, at some future date, would have a more substantial impact on intersection operations. Conclusions Our analysis of additional traffic impacts associated with land use changes in Phase 2 of the Nexus Point Subdivision has concluded that the changes are minor and would not change the conclusions contained within the original TIS. If additional information is desired, feel free to contact me. Robert R. Marvin, P.E., P.T.O.E. HCS Two-Way Stop-Control Report General Information Site Information Analyst R Marvin Intersection S 19th & Arnold Agency/Co.Marvin & Associates Jurisdiction City of Bozeman Date Performed 1/21/2023 East/West Street Arnold Street Analysis Year 2019 North/South Street S 19th Avenue Time Analyzed Peak AM Existing Plus Peak Hour Factor 0.92 Intersection Orientation North-South Analysis Time Period (hrs)0.25 Project Description Nexus Points & Graf Apartments Lanes Major Street: North-South 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 10 11 12 7 8 9 1U 1 2 3 4U 4 5 6 Number of Lanes 0 1 0 0 0 0 0 1 2 0 0 0 2 0 Configuration LR L T T TR Volume (veh/h)95 18 0 9 678 305 42 Percent Heavy Vehicles (%)0 0 0 0 Proportion Time Blocked Percent Grade (%)0 Right Turn Channelized Median Type | Storage Left Only 1 Critical and Follow-up Headways Base Critical Headway (sec)7.5 6.9 4.1 Critical Headway (sec)6.80 6.90 4.10 Base Follow-Up Headway (sec)3.5 3.3 2.2 Follow-Up Headway (sec)3.50 3.30 2.20 Delay, Queue Length, and Level of Service Flow Rate, v (veh/h)123 10 Capacity, c (veh/h)498 1192 v/c Ratio 0.25 0.01 95% Queue Length, Q₉₅ (veh)1.0 0.0 Control Delay (s/veh)14.6 8.0 Level of Service (LOS)B A Approach Delay (s/veh)14.6 0.1 Approach LOS B A Copyright © 2023 University of Florida. All Rights Reserved. HCS™TWSC Version 2023 Generated: 1/21/2023 2:45:34 PMS19th & Arnold AM Exist Plus Update.xtw HCS Two-Way Stop-Control Report General Information Site Information Analyst R Marvin Intersection S 19th & Arnold Agency/Co.Marvin & Associates Jurisdiction City of Bozeman Date Performed 1/21/2023 East/West Street Arnold Street Analysis Year 2019 North/South Street S 19th Avenue Time Analyzed Peak PM Existing Plus Peak Hour Factor 0.92 Intersection Orientation North-South Analysis Time Period (hrs)0.25 Project Description Nexus Points & Graf Apartments Lanes Major Street: North-South 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 10 11 12 7 8 9 1U 1 2 3 4U 4 5 6 Number of Lanes 0 1 0 0 0 0 0 1 2 0 0 0 2 0 Configuration LR L T T TR Volume (veh/h)67 13 0 19 411 625 99 Percent Heavy Vehicles (%)0 0 0 0 Proportion Time Blocked Percent Grade (%)0 Right Turn Channelized Median Type | Storage Left Only 1 Critical and Follow-up Headways Base Critical Headway (sec)7.5 6.9 4.1 Critical Headway (sec)6.80 6.90 4.10 Base Follow-Up Headway (sec)3.5 3.3 2.2 Follow-Up Headway (sec)3.50 3.30 2.20 Delay, Queue Length, and Level of Service Flow Rate, v (veh/h)87 21 Capacity, c (veh/h)374 841 v/c Ratio 0.23 0.02 95% Queue Length, Q₉₅ (veh)0.9 0.1 Control Delay (s/veh)17.5 9.4 Level of Service (LOS)C A Approach Delay (s/veh)17.5 0.4 Approach LOS C A Copyright © 2023 University of Florida. All Rights Reserved. HCS™TWSC Version 2023 Generated: 1/23/2023 1:23:07 PMS19th & Arnold PM Exist Plus Update.xtw