appendix B fehr & peers report Sonoma Boulevard Corridor Design Plan - Final Chapter 2 – Existing Conditions August 2012 2.3 CIRCULATION, TRANSPORTATION, AND PARKING The existing conditions chapter presents the physical and operational characteristics of the transportation system within the project corridor. The project corridor is shown in Figure 1. 2.3.1 Street Network Regional Network State Route 29 (SR-29) is a major north-south highway that connects Napa County to the north, and Lake County to the north of Napa County and Interstate 80 (I-80) in Vallejo to the south. Through Vallejo, SR-29 is Sonoma Boulevard. It runs along the western side of the City, providing two travel lanes in each direction. Sonoma Boulevard is a divided roadway north of Couch Street with a posted speed limit of 40 mph. It is undivided south of Couch Street, with a posted speed limit of 35 mph between Couch Street and Illinois Street and 30 mph south of Illinois Street. The annual average daily traffic (AADT) increases going north along Sonoma Boulevard, from 12,300 vehicles at Maine Street to 16,000 vehicles at Tennessee Street and 27,000 vehicles at the SR-37 junction1. Sonoma Boulevard is part of the state truck network and is designated as a Terminal Access (TA) route, which permit large STAA-designated trucks2. The average annual daily truck traffic (AADTT) increases going north, from 460 vehicles at Maine Street to 520 vehicles at Tennessee Street and 710 vehicles at the SR-37 junction1. State Route 37 (SR-37) is an east-west highway that connects Highway 101 (US-101) in Novato to the west and Interstate 80 (I-80) in Vallejo to the east. In the vicinity of the project, SR-37 is a restricted access freeway that provides two travel lanes in each direction. The posted speed limit is 65 mph. Access to Sonoma Boulevard is provided via the SR-37/SR-29 interchange in northern Vallejo. The annual average daily traffic is 30,500 vehicles west of the SR-37/SR-29 interchange and 65,000 vehicles east of the interchange1. Local Street System Curtola Parkway is a 4-lane east-west arterial road that extends between Mare Island Way to the west and Interstate 780 (I-780) to the east. In the vicinity of the project corridor, the posted speed limit is 35 mph to the west and 40 mph to the east of Sonoma Boulevard. Georgia Street is an east-west collector street that extends between Mare Island Way to the west and Ascot Parkway east of I-80. In the project area, it is 2-lanes to the west of Sonoma Boulevard and 4- lanes to the east. The posted speed limit is 25 mph. Redwood Street is a 4-lane, east-west arterial road that extends between Sacramento Street to the west and I-80 to the east. In the vicinity of the project corridor, the posted speed limit is 30 mph. Sereno Drive is a 4-lane east-west collector street that extends between White Slough to the west and Fairgrounds Drive to the east. In the vicinity of the project corridor, the posted speed limit is 25 mph. 1 Caltrans, 2010, http://traffic-counts.dot.ca.gov/. 2 Surface Transportation Assistance Act (STAA) of 1982 legalized operation of large STAA-designated trucks with a 48-foot semitrailer, an unlimited overall length, and an unlimited kingpin-to-rear-axle (KPRA) distance on the National Network. 1 Sonoma Boulevard Corridor Design Plan - Final Chapter 2 – Existing Conditions August 2012 Tennessee Street is a 4-lane, east-west arterial road that extends between Mare Island Way to the west and Columbus Parkway to the east. In the vicinity of the project corridor, the posted speed limit is 30 mph. 2.3.2 Traffic Operations Traffic operations for the study area were analyzed using the Synchro (Version 7) software program. Synchro is based on procedures outlined in the Transportation Research Board's 2000 Highway Capacity Manual (HCM). The results of the analysis include a descriptive term known as level of service (LOS). LOS is a measure of traffic operating conditions, which varies from LOS A (indicating free flow traffic conditions with little or no delay) to LOS F (representing over-saturated conditions where traffic flows exceed design capacity resulting in long queues and delays). Table 2-1 summarizes the relationship between the average control delay per vehicle and LOS for signalized intersections. TABLE 2-1 INTERSECTION LEVEL OF SERVICE THRESHOLDS Signalized Intersection Control Delay Level of Service General Description (sec/veh)1 A 0 – 10.0 Little to no congestion or delays. B 10.1 – 20.0 Limited congestion. Short delays. C 20.1 – 35.0 Some congestion with average delays. D 35.1 – 55.0 Significant congestion and delays. E 55.1 – 80.0 Severe congestion and delays. F > 80.0 Total breakdown with extreme delays. Notes: 1. Control delay includes initial deceleration delay, queue move-up time, stopped delay, and acceleration delay. Source: Highway Capacity Manual, Chapter 16 (Signalized Intersections), Transportation Research Board, 2000. Traffic operations was evaluated at six major intersections along the Project corridor including: 1. Sonoma Boulevard / SR-37 Westbound Ramps 2. Sonoma Boulevard / SR-37 Eastbound Ramps 3. Sonoma Boulevard / Redwood Street 4. Sonoma Boulevard / Tennessee Street 5. Sonoma Boulevard / Georgia Street 6. Sonoma Boulevard / Curtola Parkway The analysis was performed for three scenarios including Existing (No Project), Existing With Project, and Future With Project conditions. The Project scenarios assume that the North/Central North corridors provide two travel lanes in each direction and that a road diet is implemented in the South/Central South corridors to provide one travel lane in each direction. 2 Sonoma Boulevard Corridor Design Plan - Final Chapter 2 – Existing Conditions August 2012 Existing Conditions The existing conditions analysis was based on AM and PM peak hour traffic counts collected between 7-9 AM and 4-6 PM in August 2011. Existing peak hour traffic volumes and lane configurations are presented in Figure 2. Table 2-2 presents the intersection level of service results for all six study intersections. As shown, all study intersections are currently operating at LOS C or better during both AM and PM peak hours. TABLE 2-2 EXISTING CONDITIONS INTERSECTION PEAK HOUR LEVELS OF SERVICE Peak Location Control Delay2 LOS3 Hour AM 16 B 1. Sonoma Boulevard / SR-37 Westbound Ramps Signal PM 24 C AM 21 C 2. Sonoma Boulevard / SR-37 Eastbound Ramps Signal PM 30 C AM 17 B 3. Sonoma Boulevard / Redwood Street Signal PM 27 C AM 18 B 4. Sonoma Boulevard / Tennessee Street Signal PM 22 C AM 13 B 5. Sonoma Boulevard / Georgia Street Signal PM 15 B AM 17 B 6. Sonoma Boulevard / Curtola Parkway Signal PM 19 B Source: Fehr & Peers, May 2012. Project Conditions Future (Year 2030) traffic volumes were derived from the Solano Transportation Authority (STA) Travel Demand Model (TDM). The base year and future year model projections were used to calculate annual growth rates which were applied to the existing traffic counts. Figures 3 and 4 presents the Existing With Project and Future With Project peak hour traffic volumes and lane configurations assuming the proposed geometric improvements are implemented at the study intersections. Table 2-3 presents the level of service results under Existing With Project and Future With Project conditions. The Existing No Project results are also provided in the table. As shown, under all scenarios, all six study intersections are anticipated to operate at LOS D or better during the weekday AM and PM peak hours. More detailed analyses (i.e. corridor-wide microsimulation, multi-modal level of service) is recommended to assess the potential impacts of the proposed improvements on operations along the corridor. Based on the traffic operations analysis, northbound and southbound right-turn pockets are not necessary at the study intersections along the project corridor. However, right-turn pockets would improve operations and should be considered where curb extensions are not provided. 3 Sonoma Boulevard Corridor Design Plan - Final Chapter 2 – Existing Conditions August 2012 Based on the projected growth derived from the STA model, the future year Annual Daily Traffic (ADT) is between 15,000 and 19,500 in the South and Central South corridors and between 26,000 and 33,000 in the North and Central North corridors. The proposed road diet along the South and Central South corridors can accommodate the anticipated future demand. Many cities have successfully implemented road diets on facilities that served up to 23,000 daily vehicles. For the North and Central North corridors, four lane divided arterial roadways have a two-way capacity of approximately 35,000 daily vehicles so the future demand can be accommodated. 4 Sonoma Boulevard Corridor Design Plan - Final Chapter 2 – Existing Conditions TABLE 2-3 INTERSECTION PEAK HOUR LEVELS OF SERVICE COMPARISON Future (Year 2030) With Peak Existing No Project Existing With Project Location Control Project Hour Delay LOS Delay LOS Delay LOS 1. Sonoma Boulevard / SR-37 Westbound AM 16 B 16 B 25 C Signal Ramps PM 24 C 24 C 48 D 2. Sonoma Boulevard / SR-37 Eastbound AM 21 C 21 C 24 C Signal Ramps PM 30 C 30 C 48 D AM 17 B 19 B 21 C 3. Sonoma Boulevard / Redwood Street Signal PM 27 C 28 C 44 D AM 18 B 22 C 27 C 4. Sonoma Boulevard / Tennessee Street Signal PM 22 C 29 C 38 D AM 13 B 14 B 14 B 5. Sonoma Boulevard / Georgia Street Signal PM 15 B 17 B 19 B AM 17 B 17 B 19 B 6.