Transportation System Plan 2018-2038

stop line. LOS ranges from A to F, with A indicating the most desirable condition and F indicating an unsatisfactory condition. The HCM LOS designations for signalized and stop-controlled intersections are provided in Tables G-1 and G-2 respectively . Table G-1 HCM Level of Service Designations for Signaliz ed Intersections Level of Serv ice Traffic Flow Comments Delay Range A (Desirable) Free Traffic flows freely with minimal or no delay. Drivers can maneuver easily and find freedom in operation. ≤ 10 B (Desirable) Stable Traffic still flows smoothly with few delays. Some drivers feel somewhat restricted within groups of vehicles. > 10 and ≤ 20 C (Desirable) Stable Traffic generally flows smoothl y but occasionally vehicles may be delayed through one signal cycle. Desired urban area design level. Backups may develop behind turning vehicles. Most drivers f eel somewhat restricted. > 20 and ≤ 35 D (Acceptable) Approaching Unstable Traffic delays may be more than one signal cycle during peak hours but excessive back-ups do not occur. Considered acceptable urban area design level. > 35 and ≤ 55 E (Unsatisfactory) Unstable Delay may be great and up to several signal cycles. Short periods of this leve l may be tolerated during peak hours if improvement is costly and disruptive. There are typically long queues of vehicl es waiting upstream of the inters ections . > 55 and ≤ 80 F (Unsatisfactory) Forced Excessive delay causes r educed capacity. Always considered unsatisfactory. May be tolerated in recreational areas where occurrence is rare. Traffic is backed up from other locations and may restrict or prevent movement of vehicles at the intersection. ≥ 80 Delay Range relates to the range of average vehicle delay (in seconds per vehicle) that falls w ithin the associated level of service. Table G-2 HCM Level of Service Designations for Unsignaliz ed Intersections Level of Serv ice Delay Range A (Desirable) ≤ 10 B (Desirable) > 10 and ≤ 15 C (Desirable) > 15 and ≤ 25 D (Acceptable) > 25 and ≤ 35 E (Undesirable) > 35 and ≤ 50 F (Unsatisfactory) ≥ 50 Delay Range relates to the range of average vehicle delay (in seconds per vehicle) that falls w ithin the asso ciated level of service. Intersection v/c ratio provides an indication of capacity sufficiency at an intersec tion. When the v/c ratio exceeds 1.0, the am ount of auto dem and at the facility exceeds the capacity of the facility to serve that demand. Poor levels of service are often experienced when the v/c ratio exceeds 1.0. G-4