Saticoy & Wells Community Plan & Development ... - City Of Ventura

Saticoy & Wells Community Plan and Code EIRSection 4.15 Traffic and CirculationTable 4.15-2Intersection Level of Service DescriptionsLOSDescriptionDelay perVehicle(sec.)ICU RangeABCDEFLOS A describes operations with low control delay, up to 10seconds per vehicle. This LOS occurs when progression isextremely favorable and most vehicles arrive during the greenphase. Many vehicles do not stop at all. Short cycle lengths maytend to contribute to low delay values.LOS B describes with control delay greater than 10 and up to 20seconds per vehicle. This level generally occurs with goodprogression, short cycle lengths, or both. More vehicles stop thanthe LOS A, causing higher levels of delay.LOS C describes operations with control delay greater than 20 andup to 35 seconds per vehicle. These higher delays may result fromonly fair progression, longer cycle lengths, or both. Individual cyclefailures may begin to appear at this level. Cycle failure occurswhen a given green phase does not serve queued vehicles, andoverflows occur. The number of vehicles stopping is significant atthis level, though many still pass through the intersection withoutstopping.LOS D describes operations with control delay greater than 35 andup to 55 seconds per vehicle. At LOS D, the influence ofcongestion becomes more noticeable. Longer delays may resultfrom some combination of unfavorable progression, long cyclelengths, and high V/C ratios. Many vehicles stop, and theproportion of vehicles not stopping declines. Individual cyclefailures are noticeable.LOS E describes operations with control delay greater than 55 andup to 80 seconds per vehicle. These high delay values generallyindicate poor progression, long cycle lengths, and high V/C ratios.Individual cycle failures are common.LOS F describes operations with control delay in excess of 80seconds per vehicle. This level, considered unacceptable to mostdrivers, often occurs with oversaturation, that is, when arrival flowrates exceed the capacity of lane groups. It may also occur at highV/C ratios with many individual cycle failures. Poor progressionand long cycle lengths may also contribute significantly to highdelay levels.< 10 0.00 – 0.6010 - 20 0.61 – 0.7020 - 35 0.71 – 0.8035 - 55 0.81 – 0.9055 - 80 0.91 – 1.00> 80 > 1.00Source: Highway Capacity Manual 2000, Transportation Research Board, National Research Council.4.15-4City of Ventura