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23 <br />consistency against existing land use maps and were reviewed by local planning department <br />staff. <br />Forecasts were prepazed by local planning department staff with guidance from staff at the two <br />MPO's. A regional methodology was applied to maintain consistency between residential and <br />employment forecasts and adopted land use plans. Data and forecasts were submitted for public <br />review by each MPO, and adopted for use in developing travel demand and air quality forecasts <br />by each MPO's Transportation Advisory Committee. <br />The Triangle Regional Travel Demand Model (TRM) uses the basic four-step process (trip <br />generation, trip distribution, mode choice and assignment). All four steps of the process are <br />discussed in greater detail in the sections below. The Triangle Regional Model was calibrated to <br />2005 conditions. Because some of the projects are proposed toll roads, the TRM TransCAD model <br />was updated to include toll capability in order to estimate travel changes associated with tolling on <br />these facilities. <br />The Triangle Regional Model's TransCAD model is housed at the Institute for Transportation <br />Research and Education (TYRE) at NC State University. The TransCAD model covers all of <br />Durham, Wake and Orange Counties (including the portions within the BG MPO and the <br />Triangle Area RPO), all of the portion of Chatham County that is in the Triangle ozone <br />maintenance area, and portions of Franklin, Granville and Johnston counties (which aze in the <br />maintenance area) along with a portion of Harnett County (which is not part of the maintenance <br />area). <br />Outside of the modeled area, NCDOT utilizes a spreadsheet that incorporates the vehicle-miles <br />traveled (VMT) universe file and historical trends to project the VMT in future years at the county <br />level. The spreadsheet calculates speed based on a model originally developed by the Texas <br />Transportation Institute but modified by NCDOT. Speeds generated by the spreadsheet aze <br />incorporated into the MOBILE6.2 emissions program. Then, emission factors developed by <br />Mobile6.2 are imported into the spreadsheet and multiplied by forecasted VMT to generate <br />emissions. The rural spreadsheet model is used for all of Person County and is factored based on <br />population percentage for those portions of non-attainment. counties not covered by the TransCAD <br />model. This methodology has been used to demonstrate conformity in other azeas and has <br />received approval from interagency partners. <br />There are no court orders or special agreements that apply to conformity (40 CFR 93.109). <br />3.4 Future year roadway oroiects <br />Roadway improvements used for conformity modeling were developed in the 2035 Transportation <br />Plan process in each MPO. Outside of the MPO boundaries, TIP projects from the 2009-2015 TIP <br />served as the future yeaz roadway projects. For the 2035 Plans, lists of needed projects were <br />developed based on modeled congestion and identified local needs. Improvements were coded <br />into the TRM and analyzed. Intermediate analysis for the years 2015 and 2025 were performed to <br />assist in prioritizing the 2035 roadway needs. The fina12015, 2025, and 2035 networks aze <br />fiscally constrained. Projects were added from MPO priority lists until estimated project costs <br />equaled the expected funding available. The base network (2005) and the three future networks <br />15 <br />