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Mike Tassano January 31, 2025 Page 13 of 37 Intersection LOS – Key Locations Intersections are generally the critical capacity-controlling elements of suburban roadway networks. Therefore, the operations of critical intersections surrounding the study area are used as indicators of the adequacy of the vehicular circulation system. The following intersections, also shown on Figure 6, were selected to analyze the potential effects of the El Charro Road extension during the weekday morning (7:00 to 9:00 AM) and weekday evening (4:00 to 6:00 PM) peak periods. 1. Santa Rita Road at W Las Positas Boulevard 2. Santa Rita Road at Stoneridge Drive 3. Santa Rita Road at Valley Avenue 4. Main Street at Stanley Boulevard 5. First Street at Vineyard Avenue 6. First Street/Sunol Boulevard at Bernal Avenue 7. Bernal Avenue at Vineyard Avenue 8. Bernal Avenue/Valley Avenue at Stanley Boulevard 9. El Charro Road at Stanley Boulevard 10. El Charro Road at Stoneridge Drive 11. Isabel Avenue at Stanley Boulevard 12. Busch Road at Valley Avenue 13. Santa Rita Road at I-580 westbound ramps 14. Santa Rita Road at I-580 eastbound ramps/Pimlico Drive 15. Sunol Boulevard at I-680 northbound ramps 16. Sunol Boulevard at I-680 southbound ramps The operations of roadway facilities are described with the term “level of service” (LOS). LOS is a qualitative description of traffic flow from a vehicle driver’s perspective based on factors such as speed, travel time, delay, and freedom to maneuver. Six levels of service are defined, ranging from LOS A (free-flow conditions) to LOS F (over-capacity conditions). LOS E corresponds to operations “at capacity.” When volumes exceed capacity, stop-and-go conditions result, and operations are designated LOS F. Traffic conditions at signalized intersections were evaluated using methods developed by the Transportation Research Board (TRB), as documented in the Highway Capacity Manual (HCM), 2000 Edition, for vehicles. The HCM method calculates control delay at an intersection based on inputs such as traffic volumes, lane geometry, signal phasing and timing, pedestrian crossing times, and peak hour factors. Control delay is defined as the delay directly associated with the traffic control device (i.e., a stop sign or a traffic signal) and specifically includes initial deceleration delay, queue move-up time, stopped delay, and final acceleration delay. The relationship between LOS and control delay is summarized in Table 2.