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LINSCOTT, LAW & GREENSPAN, engineers LLG Ref. 2-17-3881-1 Tustin Avenue Retail, Santa Ana N:\3800\2173881 - Tustin Avenue Retail, Santa Ana\Report\3881 - Tustin Avenue Retail, Santa Ana TIA 03-13-18.doc 13 4.0 TRAFFIC FORECASTING METHODOLOGY In order to estimate the traffic impact characteristics of the proposed Project, a multi-step process has been utilized. The first step is traffic generation, which estimates the total arriving and departing traffic on a peak hour and daily basis. The traffic generation potential is forecast by applying the appropriate vehicle trip generation equations or rates to the project development tabulation. The second step of the forecasting process is traffic distribution, which identifies the origins and destinations of inbound and outbound project traffic. These origins and destinations are typically based on demographics and existing/expected future travel patterns in the study area. The third step is traffic assignment, which involves the allocation of project traffic to study area streets and intersections. Traffic assignment is typically based on minimization of travel time, which may or may not involve the shortest route, depending on prevailing operating conditions and travel speeds. Traffic distribution patterns are indicated by general percentage orientation, while traffic assignment allocates specific volume forecasts to individual roadway links and intersection turning movements throughout the study area. With the forecasting process complete and project traffic assignments developed, the impact of the proposed project is isolated by comparing operational (LOS) conditions at selected key intersections using expected future traffic volumes with and without forecast project traffic. The need for site- specific and/or cumulative local area traffic improvements can then be evaluated and the significance of the project’s impacts identified. 2-78