Traffic Report

Level of Service Criteria Signalized Intersections Levels of service for a signalized intersection are determined by the computed or measured control delay and are defined for lane groups, intersection approaches and the intersections as a whole. The Highway Capacity Manual (HCM) published by the Transportation Research Board of the National Research Council, defines control delay as: “The component of delay that results when a control signal causes a lane group to reduce speed or to stop; it is measured by comparison with the uncontrolled condition.” Control delay is the portion of the total delay attributed to traffic signal operation for signalized intersections. Control delay includes initial deceleration delay, queue move-up time, stopped delay and final acceleration delay. Level of service criteria as defined by the Highway Capacity Manual is as follows. Level of Service Average Control Delay (sec./veh.) A 0-10 B >10-20 C >20-35 D >35-55 E >55-80 F >80 27