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<br />Denrlis Welsch <br />\1arch 2-i, 1997 <br />Page 21 <br /> <br />The warrant anah'ses was limited to Warrant 11 because of data constr~ints, <br /> <br />The signal '\'arrant analyses for the intersections used the 100 percent warra::t <br />requirements because the intersections are located in a community of greater <br />than 10,000 persons and Cle,'eland Asenue (40 mph) has a posted speed hmjt <br />that is not ~ -i0 mph. <br /> <br />The results C,j the signal ,\'arrant analyses are sho,\'n in Figures 10 (existing\' <br />11 (Year 2001 Background) and 12 (Year 2001 Post-Dewlopment), The data <br />indicate that none of the four intersections is expected to meet the \\-arr2nt 11 <br />requirements for the installation of a traffic signal through the Yea :001 time <br />tr ~,ne. <br /> <br />Queuing Analyses <br /> <br />'-- <br /> <br />Since the capacity analyses calculate intersection operations assuming isolc.ted <br />conditions (i.e., no nearby adjacent intersections), the expected traffic queues <br />from signalized intersections should also be analyzed in urban em'ironment." to <br />account for possible operational problems beh\'een adjacent intersections, <br />Therefore, queuing analyses were conducted for the existing, Year 2001 <br />Background and Year 2001 Post-Development P~1 peak hour conditions at <br />each of the five key signalized intersections. <br /> <br />A queuing analysis is an objective method used to estimate the s;rage <br />distance needed to accommodate the traffic demands on a per lane basis <br />during the red phase of a traffic signal cycle, The formula used to calculate <br />traffic queues at signalized intersections is described below. <br /> <br />Storage Length in feet = 2 x (vehicles per hour in lane)(l-green time of <br />phase/signal cycle length)(l+% trucks)(average \'ehicle length) / (number of <br />signal cycles per hour). <br /> <br />The factor of n'\'o at the beginning of the formula provides answers at the 95~o <br />confidence level. In general, by designing for this level, the storage ,",'ould <br />only be exceeded at most 5 % of the time during the PM peak hour. The <br />average ,'ehide length is typically considered as 20 to 25 feet. Due to the <br />relatively high percentage of trucks, 25 feet was used. <br />- - <br />