2011-022 - Addendum to the FInal Environmental Impact Report No. 2004-02

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additional units). The study incorporated the Highway Capacity Manual, 2000 Edition, methodology that is required by Caltrans for all intersection analysis. In addition, the Intersection Capacity Utilization (ICU) technique was used, which measures the amount of traffic signal "green" time required for the intersection. Street operating conditions are typically described in terms of "level of service" (LOS). LOS ranges from Level A (free flow, little congestion) to Level F (forced flow, extreme congestion). The City of Santa Ana considers LOS D as the threshold of an acceptable service level for intersections outside Major Development Areas (MDA) and LOS E as the maximum threshold for intersections located within an MDA. The City of Costa Mesa defines LOS D as an acceptable operation level for all intersections. The City of Irvine defines LOSE as acceptable for intersections within the Irvine Business Complex and LOS D or better for all other intersections. These criteria are consistent with Measure M target levels and meet or are more stringent than Congestion Management Plan (CMP) criteria. Following are the levels of service that are acceptable for the study intersections: • Main Street at Dyer Road (LOS D) • Main Street at MacArthur Boulevard (LOS E) • Main Street at Sandpointe Avenue (LOS D) • Main Street at Sunflower Avenue (LOS D) • MacArthur Place at MacArthur Boulevard (LOS E) • SR -55 SB Ramps at MacArthur Boulevard (LOS E) • SR -55 NB Ramps at MacArthur Boulevard (LOS D) • Red Hill Avenue at MacArthur Boulevard (LOS E) All traffic data used in the KOA 2011 Study was collected in October and November 2010. Peak hour intersection analysis was performed using the TRAFFIX software program by Dowling Associates. Existing traffic data was obtained from Transportation Studies, Inc. of Tustin. Long -range (2035) analysis is based on future traffic forecasts from the Orange County Transportation Authority (OCTA) travel demand forecasting model (OCTAM 3.3). The OCTAM model uses the latest adopted demographic forecasts, commonly referred to as Orange County Projections, adopted in 2006 (OCP- 2006). Detailed model data is included in the 2011 Traffic Study (Appendix B). The City of Santa Ana's project impact analysis criteria indicates that a significant project impact occurs when the ICU value increases by greater than .01 and achieves unacceptable LOS (E or F). Costa Mesa defines LOS D as an acceptable level of operation for all intersections. Irvine states that intersections within the Irvine Business Complex should operate at LOS E or better for peak hour and LOS D or better at all other intersections. In addition, projects must comply with the Orange County Congestion Management Plan (CMP) criteria. The CMP states that a project cannot be allowed to reduce LOS or increase flow by more than 3% at a location that is forecast to experience LOS E or F generally. Since this criterion is less stringent than the City's, any project that meets the City criteria will also normally meet CMP criteria. Existing Conditions Due to significant land use development in recent years, the KOA 2010 Study determined that some significant roadway and intersection improvements within the study area have changed since the original traffic study was conducted. The intersection of Main Street at MacArthur Boulevard has been recently improved and fully built out. Exclusive right turn lanes have been constructed for all approaches to the intersection. Table 1 depicts the AM (7:00 a.m. to 9:00 a.m.) and PM (4:00 p.m. to 6:00 p.m.) peak hour conditions. MacArthur Place South EIR — 2011 Addendum 37