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Highway Capacity Manual (HCM) Methodology <br />In response to intersection queuing observed in the vicinity of the proposed project, the LOS at the signalized <br />study area intersections was also measured using the methodology contained in the Highway Capacity <br />Manual, 2000 Edition. The 2000 HCM methodology utilizes average delay per vehicle based upon peak hour <br />traffic volumes, peak hour factors, number of lanes, type of operation, etc. in the calculation. Specific signal <br />timing parameters for each intersection were provided by City of Santa Ana Traffic staff. The HCM <br />methodology was implemented using the Highway Capacity software. <br />The qualitative A through F level of service scale for the HCM is measured quantitatively using measures of <br />e,~`ectiveness. The measure used depends on the type of facility being assessed. A summary of each Level of <br />Service and the corresponding control delay is provided in the chart below: <br />HCM LEVEL OF SERVICE SUMMARY <br />Level of Service Signalized Intersections: <br />Avera a Dela er Vehicle sec <br />A <10 <br />B > 10 and < 20 <br />C > 20 and _< 35 <br />D >35and<55 <br />E > 55 and < 80 <br />F > 80 <br />Source: Highway Capacity Manual, 2000 <br />LEVEL OF SERVICE STANDARDS <br />The City of Santa Ana considers the maximum threshold to be LOS "E" for those intersections located within <br />the Major Development Areas (MDA). For locations outside the MDA, the City's LOS standard is LOS "D". <br />A project is considered to have a significant impact at an intersection if the traffic LOS deteriorates to an <br />unacceptable LOS (LOS "E" or "F'~ with the addition of project traffic. Improvements are required for <br />locations that operate at acceptable LOS without the project, but with the addition of project traffic drop to <br />unacceptable LOS. Locations that are forecasted to operate worse than acceptable LOS even without the <br />project, the traffic assessment must include improvements to achieve acceptable LOS per the City of Santa <br />Ana's standards. <br />Traffic Analysis for - 3 - October, 2007 <br />Alton Court Residential Development <br />75A-134 <br />