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Project Study Methodology <br />• Main Street at Dyer Road (LOS D) <br />• Main Street at MacArthur Boulevard (LOS E) <br />• Main Street at Sandpointe Avenue (LOS D) <br />• Main Street at Sunflower Avenue (LOS D) <br />• MacArthur Place at MacArthur Boulevard (LOS E) <br />• SR-55 SB Ramps at MacArthur Boulevard (LOS E) <br />• SR-55 NB Ramps at MacArthur Boulevard (LOS D) <br />• Red Hill Avenue at MacArthur Boulevard (LOS E) <br />The specific assumptions for the ICU analysis include the use of a saturation flow value of 1,700 vehicles <br />per lane per hour (VPLPH), with the exception of those intersections in the City of Costa Mesa where a <br />saturation flow value of 1,600 VPLPH is used to be consistent with the City of Costa Mesa procedures. <br />No capacity adjustments are applied to protected movements with dedicated lanes (including both right <br />and left turns), except within the City of Santa Ana, where a reduced capacity of 1,600 vehicles per lane <br />per hour is used for dedicated turn lanes. In the City of Irvine, free right-turn lanes are assumed within <br />the analysis wherever dedicated approach and departure lanes exist, regardless of the presence or <br />absence of yield signs. A loss time factor of 5 percent is applied to the ICU calculations for all <br />jurisdictions except the City of Costa Mesa, where no loss time is assumed. Finally, a "de facto" right- <br />turn lane is assumed to exist when the outermost through lane is 19 feet or greater in width and <br />parking is prohibited. <br />The analysis of peak hour intersection conditions was conducted using the TRAFFIX software program <br />developed by Dowling Associates. The following peak periods were selected for analysis: <br />• Weekday AM (peak hour between 7:00 AM and 9:00 AM) <br />• Weekday PM (peak hour between 4:00 PM and 6:00 PM) <br />Traffic Count Data <br />Existing traffic data was obtained from Transportation Studies, Inc. of Tustin. All traffic count data used <br />in this study was collected in October and November, 2010 and is complied in Appendix B of this <br />report. <br />Long Range Traffic Volume Forecasts <br />The long range (2035) analysis is based on future traffic forecasts obtained from the Orange County <br />Transportation Authority (OCTA) travel demand forecasting model (OCTAM 3.3). Since the original <br />traffic study was completed, the OCTAM model has been updated and the long range condition is now <br />represented as 2035 conditions. To be consistent, a new model run has been obtained from OCTA to <br />assist in the focused traffic study. <br />OCTAM 3.3 is OCTA's travel demand forecasting model. It is used to evaluate circulation and transit <br />system needs throughout the County of Orange. The OCTAM 3.3 model consists of a 2,940 traffic <br />PF KOA CORPORATION Updated Main and MacArthur Development Project <br />PLANNING $ ENGINEERING 6 Traffic Impact Study in City of Santa Ana <br />75B-138