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The intersections will be evaluated using the Intersection Capacity Utilization (ICU) methodology, as specified by the City of Santa Ana traffic guidelines, and using the Highway Capacity Manual (HCM) methodology, which provides an indication of delay in seconds for all vehicles entering an intersection. Intersection Capacity Utilization {ICU) Methodology In accordance with the City of Santa Ana requirements, peak hour operating conditions at the signalized intersections were evaluated using the ICU methodology. The ICU methodology provides a comparison of the theoretical hourly vehiculaz capacity of an intersection to the number of vehicles actually passing through that intersection during a given hour. Based on City of Santa Ana analysis criteria, the ICU calculation assumes aper-lane capacity of 1,700 vehicles per hour (vph) for each through h~avel lane and 1,600 for fuming lanes. Where there is no separately- striped right-tum lane, if the width of the outside through lane is 19 feet or more, and parking is prohibited during the peak period, a separate right-turn lane is assumed. A clearance factor of 0.05 (5%) of the total intersection capacity is included in the ICU calculation, to account for the effect of the red and yellow signal phases at a signalized intersection. The ICU calculation generates avolume-to-capacity (V/C) ratio that translates into a corresponding Level of Service (LOS) measure, ranging from LOS "A", representing uncongested, free-flowing conditions, to LOS "F", representing over-capacity conditions. A summary description of each Level of Service and the corresponding V/C ratio is provided on the following chart: LEVEL OF SERVICE DESCRIPTIONS SIGNALIZED INTERSECTIONS Level of ICU Value Description Service A 0.00 - 0.60 Excellent operation. All approaches to the intersection appear quite open, turning movements are Basil made and near) all drivers find freedom of o ation. Very good operation. Many drivers begin to feel somewhat restricted within B 0.61 - 0.70 platoons of vehicles. This represents stable flow. An approach to an intersection ma occasional) be full utilized and traffic eues start to form. C 0.71 - 0.80 Good operation. Occasionally drivers may have to wait more than 60 seconds, and back-u s ma develo behind vehicles. Most drivers feel somewhat restricted Fair operation. Cars are sometimes required to wait more than 60 seconds during D 0.81 - 0.90 short peaks. There are no long-standing traffic queues. This level is typically associated with desi ractice for eriods. E 0.91 - 1.00 PO°r operation. Some long-standing vehicular queues develop on critical approaches to intersections. Dela s ma be u to several minutes. Force flow. Represents jammed conditions. Back-up from locations downstream or F Over 1.00 on the cross street may restrict or prevent movement of vehicles out of the intersection a roach lanes. Source: City of Santa Ana Public Works Agency: Transportation & Development Services Division Traffic Analysis for - 2 - October, 2007 Alton Court Residential Development 75A-133