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r. <br /> 01 <br /> Table 1: Signalized Intersection LOS Criteria <br /> Level of Description Delay in <br /> Service Seconds <br /> Progression is extremely favorable,and most vehicles arrive during the green <br /> A phase. Most vehicles do not stop at all.Short cycle lengths may also contribute to < 10.0 <br /> low delay. <br /> 8 Progression is good,cycle lengths are short,or both. More vehicles stop than with > 10.0 to <br /> LOS A,causing higher levels of average delay. 20.0 <br /> Higher congestion may result from fair progression, longer cycle lengths,or both. > 20.0 to <br /> C Individual cycle failures may begin to appear at this level,though many still pass 35.0 <br /> through the intersection without stopping. <br /> The influence of congestion becomes more noticeable.Longer delays may result <br /> p from some combination of unfavorable progression, long cycle lengths,or high V/C > 35.0 to <br /> ratios. Many vehicles stop,and the proportion of vehicles not stopping declines. 55.0 <br /> Individual cycle failures are noticeable. <br /> This level is considered by many agencies to be the limit of acceptable delay.These > 55.0 to <br /> E high delay values generally indicate poor progression, long cycle lengths,and high 80.0 <br /> V/C ratios. Individual cycle failures are frequent occurrences. <br /> This level is considered unacceptable with oversaturation,which is when arrival flow <br /> rates exceed the capacity of the intersection.This level may also occur at high V/C <br /> E ratios below 1.0 with many individual cycle failures.Poor progression and long cycle ' 80.0 <br /> lengths may also be contributing factors to such delay levels. <br /> Source:Highway Capacity Manual 2000 Edition(Transportation Research Board). <br /> Table 2: Unsignalized Intersection LOS Criteria <br /> Level of Service Description Delay in Seconds <br /> A Little or no delays <_ 10.0 <br /> 8 Short traffic delays > 10.0 to 15.0 <br /> C Average traffic delays > 15.0 to 25.0 <br /> Long traffic delays > 25.0 to 35.0 <br /> E Very long traffic delays > 35.0 to 50.0 <br /> Extreme traffic,delays where intersection capacity <br /> exceeded > 50.0 <br /> Source:Highway Capacity Manual 2000 Edition(Transportation Research Board). <br />