21 ATTACHMENT 08 - Laserfiche WebLink

Dowling Associates, Inc. ~r~. Transportation Engineering • Planning • Research • Education Existing+Approved Levels of Service Level of Service is a qualitative indication of the level of delay and congestion experienced by motorists using an intersection. Levels of service are designated by the letters A through F, with A being the best conditions and F being the worst (in terms of congestion and delay). LOS A, B, C and D are considered to have congestion levels in the acceptable range, while LOS E and F are considered unacceptable. At unsignalized intersections where only the minor street approaches are controlled, most of the major street traffic is undelayed and, by definition, have acceptable conditions. The major street I left-turn movements and the minor street movements are all susceptible to delay of varying degrees. Generally, the higher the major street traffic volumes, the higher the delay for the `~` minor movements. The LOS calculation methodology from the Highway Capacity Manual (HCM), Transportation Research Board, 2000, provides a delay value and level of service for '' each of these minor movements at the intersection. Table 1 shows the average delay criteria used ' ~ to determine the level of service at the unsignalized intersections At signalized intersections, the HCM signal operations method is used to determine the_ level of service, based on City standards. The LOS calculation methodology provides a single delay value and level of service for the intersection as a whole. The method determines an average 1 control delay per intersection for the intersection. The delay criteria for signalized intersection levels of service are shown in Table 2. The LOS calculation sheets for this analysis are presented in the Appendix. Table 1 Level of Service Criteria Unsignalized Intersections Level of Average Delay Service (seconds/veh) A 0.0 - 10.0 ?~' B 10.1 - 15.0 C 15.1 - 25.0 D 25.1 - 35.0 E 35.1 - 50.0 F >50.0 Weighted average delay Source: Highway Capacity Manual 2000 Traffic Analysis Page 7 Hoene Depot Slopping Center, Pleasanton