Laserfiche WebLink
III. MEASURES OF EFFECTIVENESS <br />The traffic operations analysis for the intersections consider the following measures to determine <br />the adequacy of the intersection design to meet acceptable operations: intersection delay/Level of <br />Service (LOS) and volume -to -capacity ratios. An explanation of each of these measures is <br />provided below: <br />A. Level of Service and Delay <br />The operational analysis results are described as a Level of Service (LOS) ranging from <br />A to F. These letters serve to describe a range of operating conditions for different types <br />of facilities. Levels of Service are calculated based on the 2010 Highway Capacity <br />Manual, which defines the level of service, based on control delay. Control delay is the <br />delay experienced by vehicles slowing down as they are approaching the intersection, the <br />wait time at the intersection, and the time for the vehicle to speed up through the <br />intersection and enter into the traffic stream. The average intersection control delay is a <br />volume weighted average of delay experienced by all motorists entering the intersection <br />on all intersection approaches. The control delay is modeled within the analysis software, <br />Trafficware Synchro/SimTraffic. Level of Service D is commonly taken as an acceptable <br />design year LOS. The level of service and its associated intersection delay for a <br />signalized and unsignalized intersection is presented below. The delay threshold for <br />unsignalized intersections is lower for each LOS compared to signalized intersections, <br />which accounts for the fact that people expect a higher level of service when at a stop - <br />controlled intersection. <br />Table 1: Level of Service Criteria <br />Prepared by: Bolton & Menk, Inc. — R16.109828 Measures of Effectiveness <br />Future Business Park <br />Page 4 <br />Signalized Intersection <br />Unsignalized Intersection <br />LOS <br />Control Delay per Vehicle (sec.) <br />Control Delay per Vehicle (sec.) <br />A <br />< 10 <br />< 10 <br />B <br />>l0and <20 <br />>l0and <15 <br />C <br />>20and <35 <br />>15 and 25 <br />D <br />>35 and < 55 <br />>25 and < 35 <br />E <br />>55 and < 80 <br />>35 and < 50 <br />F <br />>80 <br />>50 <br />Prepared by: Bolton & Menk, Inc. — R16.109828 Measures of Effectiveness <br />Future Business Park <br />Page 4 <br />