The Travel Cost Module translates changes in travel time, travel expense and accident rates into dollar cost savings that accrue to households and businesses. These may result from changes in route distances, speeds, fuel costs, fares/tolls or travel conditions.  Additional effects related to congestion, travel time reliability and air quality can also be calculated through this module, if desired. The module then segments the total savings among economic sectors based on regional industry mix and commodity use of modes.

TREDIS inputs can be generated by sketch planning methods, spreadsheets or travel demand models. The system has been used with data from a variety of travel models including CUBE Voyager, TransCAD, EMM2, TRANUS, TRIPS and HERS. It has also been used with inputs provided from custom spreadsheets and engineering worksheets.  

Results. The Direct Travel Cost benefit is calculated as the total money savings in travel costs plus the values of non-money impacts, realized by adopting the “Project” scenario instead of the “Base” Scenario. Values are calculated as the difference in impact between the two scenarios, and represent the benefit in time, expense, access, safety and environmental impacts. Overall benefits are shown by region and mode for the future target year, and distinguish the direct travel cost savings for locally-based residents and businesses. These benefits are shown by component (illustrated below). A separate report also calculates the value of these benefits by mode and by sector of the economy (distinguishing households and various industry categories).