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

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Project Study Methodology • 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) The specific assumptions for the ICU analysis include the use of a saturation flow value of 1,700 vehicles per lane per hour ( VPLPH), with the exception of those intersections in the City of Costa Mesa where a saturation flow value of 1,600 VPLPH is used to be consistent with the City of Costa Mesa procedures. No capacity adjustments are applied to protected movements with dedicated lanes (including both right and left turns), except within the City of Santa Ana, where a reduced capacity of 1,600 vehicles per lane per hour is used for dedicated turn lanes. In the City of Irvine, free right -turn lanes are assumed within the analysis wherever dedicated approach and departure lanes exist, regardless of the presence or absence of yield signs. A loss time factor of 5 percent is applied to the ICU calculations for all jurisdictions except the City of Costa Mesa, where no loss time is assumed. Finally, a "de facto" right - turn lane is assumed to exist when the outermost through lane is 19 feet or greater in width and parking is prohibited. The analysis of peak hour intersection conditions was conducted using the TRAFFIX software program developed by Dowling Associates. The following peak periods were selected for analysis: • Weekday AM (peak hour between 7:00 AM and 9:00 AM) • Weekday PM (peak hour between 4:00 PM and 6:00 PM) Tragic Count Data Existing traffic data was obtained from Transportation Studies, Inc. of Tustin. All traffic count data used in this study was collected in October and November, 2010 and is complied in Appendix 8 of this report. Long Range Tragic Volume Forecasts The long range (2035) analysis is based on future traffic forecasts obtained from the Orange County Transportation Authority (OCTA) travel demand forecasting model (OCTAM 3.3). Since the original traffic study was completed, the OCTAM model has been updated and the long range condition is now represented as 2035 conditions. To be consistent, a new model run has been obtained from OCTA to assist in the focused traffic study. OCTAM 3.3 is OCTA's travel demand forecasting model. It is used to evaluate circulation and transit system needs throughout the County of Orange. The OCTAM 3.3 model consists of a 2,940 traffic KOA CORPORATION Updated Main and MacArthur Development Project ' PLANNING % ENGINEERI�iG 6 Traffic Impact Study in City of Santa Ana