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Application of Mid-Ohio Regional Planning Commission Microsimulation Model New Starts Review Dave Schmitt, AECOM Consult, Inc. F TA has very high standards for travel demand models of Delaware County is another district, and Licking used to generate ridership forecasts for its New Starts County is its own district. Portions of the surrounding program. A model's ability to meet these standards counties, including Pickaway and Union, are in the final must be assessed early on so that potential FTA concerns district. with the forecasts or model structure can be addressed in a timely manner. Model structure changes require long, iter- ative development times. TRAVEL DISTRIBUTION The Mid-Ohio Regional Planning Commission (MORPC) microsimulation model is being used to gen- Travel distribution is one of the most difficult aspects of erate forecasts for the North Corridor Transit Project travel demand to model effectively. FTA has identified (NCTP)--currently in the stage requiring a draft envi- travel distribution as a potential upstream model error ronmental impact statement--with a potential New that can lead to poorly calibrated mode choice models Starts submittal within the next few years. The NCTP is containing large, unexplainable alternative-specific con- analyzing various travel modes along a 13-mi corridor stants. To explore the reliability of the work component that includes three major employment centers inter- of the distribution model, the simulated Year 2000 work spersed with large residential areas: the central business tour distribution was compared with the 2000 Census district (CBD), Ohio State University (OSU), and the Transportation Planning Package (CTPP), which cap- Crosswoods and Polaris areas. tures work journeys. The first step was to compare the NCTP team members investigated many areas of the regionwide magnitude of modeled work trip tours to MORPC model, including its overall structure, automo- CTPP. On a regionwide basis, the model estimated bile and transit travel times, path building parameters, 660,031 work tours compared with 630,550 CTPP mode choice coefficient values, and results. The analysis records--a difference of only 4.7%. Next, district-to- of the model's trip distribution and user benefit results district tours were compared with the CTPP (scaled so will be discussed, as these two elements have been iden- that regional CTPP records match modeled journeys). tified as concerns by the FTA on other New Starts The modeled work tour distribution is shown in Table 1. projects. The CTPP journey distribution is shown in Table 2. The regional figures were divided into 13 districts for Table 3 displays the ratio of the modeled to the observed analysis purposes (Figure 1). Six districts are for the cor- distribution. ridor: CBD, the OSU area, Clintonville, Worthington, Overall, the modeled trip distribution for work pur- Crosswoods, and Polaris. The remaining area of poses appeared to be as good as or better than that of Franklin County is divided into four districts: northwest, comparable models used elsewhere in the United States. northeast, southeast, and southwest. The remaining area The model was representing trips to the CBD very 37