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Mike Tassano December 6, 2022 <br />Page 5 of 39 <br />Analysis Methods <br />The operations of roadway facilities are described with the term “level of service” (LOS). LOS is a <br />qualitative description of traffic flow from a vehicle driver’s perspective based on factors such as <br />speed, travel time, delay, and freedom to maneuver. Six levels of service are defined ranging from <br />LOS A (free-flow conditions) to LOS F (over-capacity conditions). LOS E corresponds to operations <br />“at capacity.” When volumes exceed capacity, stop-and-go conditions result, and operations are <br />designated LOS F. <br />Signalized Intersections <br />Traffic conditions at signalized intersections were evaluated using methods developed by the <br />Transportation Research Board (TRB), as documented in the Highway Capacity Manual 2000 <br />Edition for vehicles. The HCM method calculates control delay at an intersection based on inputs <br />such as traffic volumes, lane geometry, signal phasing and timing, pedestrian crossing times, and <br />peak hour factors. Control delay is defined as the delay directly associated with the traffic control <br />device (i.e., a stop sign or a traffic signal) and specifically includes initial deceleration delay, queue <br />move-up time, stopped delay, and final acceleration delay. The relationship between LOS and <br />control delay is summarized in Table 1. <br />Unsignalized Intersections <br />For unsignalized (all-way stop controlled and side-street stop controlled) intersections, the HCM <br />2000 method for unsignalized intersections was used. With this method, operations are defined <br />by the average control delay per vehicle (measured in seconds). The control delay incorporates <br />delay associated with deceleration, acceleration, stopping, and moving up in the queue. Table 2 <br />summarizes the relationship between LOS and delay for unsignalized intersections. At side-street <br />stop-controlled intersections, the delay is calculated for each stop-controlled movement, the left <br />turn movement from the major street, as well as the intersection average. The intersection <br />average delay and highest movement/approach delay are reported for side-street stop- <br />controlled intersections. <br />