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Project Study Methodology <br />Since the purpose of the study is to examine the possible impact of increasing the number of housing <br />units in the condominium project from 276 to 300 dwelling units, the study scope has been limited to <br />intersection analysis only. No roadway segment ADT or ramp and freeway mainline analysis is <br />proposed to be conducted for this study. <br />Analysis Methodologies <br />This section presents a brief overview of traffic analysis methodologies and concepts used in this study. <br />Street system operating conditions are typically described in terms of "level of service." Level of service <br />is a report -card scale used to indicate the quality of traffic flow on roadway segments and at <br />intersections. The levels of service range from Level A (free flow, little congestion) to Level F (forced <br />flow, extreme congestion). <br />Traffic conditions on most roadway facilities are analyzed using the principles of the specific analysis <br />methods contained in the Highway Capacity Manual, 2000 Edition (HCM), a publication of the <br />Transportation Research Board, a research agency affiliated with the Federal Government. Chapter 9 of <br />the HCM is devoted to analysis of signalized intersections and Chapter 10 is devoted to the analysis of <br />unsignalized intersections. The methodology in the HCM for signalized intersections is based upon <br />measurements or forecasts of control delay for traffic utilizing all approaches to the intersection. <br />Intersection average delay and poorest movement delay are reported for all unsignalized intersections. <br />Caltrans requires HCM methodology for all intersection analysis. <br />Traffic conditions in Southern California are also often evaluated at signalized intersections using a <br />methodology known as the Intersection Capacity Utilization (ICU) technique. This analysis is widely <br />accepted and essentially measures the amount of traffic signal "green" time required for the intersection. <br />It is a significant variation from the HCM method; however, it produces results that are generally similar. <br />Appendix A lists the ICU level of service criteria for signalized intersections and the HCM criteria for <br />unsignalized intersections. It also defines the level of service and ICU ranges as applied to signalized <br />intersections. <br />Based upon the Circulation and Land Use elements of the City of Santa Ana General Plan, for <br />intersections located outside of Major Development Areas (MDA), the City considers Level of Service <br />(LOS) D as the threshold of an acceptable service level and LOS E as the maximum threshold for <br />acceptable service levels for intersections located within a MDA. The City of Costa Mesa defines LOS <br />D as an acceptable traffic operation level for all intersections. The City of Irvine General Plan states that <br />roadway segments and intersections inside of the Irvine Business Complex (IBC) should operate at LOS <br />E or better for peak hour conditions. Others should operate at LOS D or better. These criteria are <br />consistent with Measure M target levels, and are either more stringent than, or meet Congestion <br />Management Plan (CMP) criteria which designates LOS E as the minimum acceptable level of service. <br />The different acceptable levels of service for the study intersections are defined below: <br />KOA CORPORATION Updated Main and MacArthur Development Project <br />PLANNING & ENGINEERING 5 Traffic Impact Study in City of Santa Ana <br />