Estimating Costs and Benefits of Transportation Corridor Alternatives

Although benefit-cost assessment is a useful tool in structuring the decision making process, it has not generally been used to assist in multi-modal decision making in metropolitan areas. Also, although detailed zone-to-zone trip information can be obtained from metropolitan travel-demand models, this information is not currently used by planners in developing detailed information on cross-modal comparisons of costs and benefits. A real-world application of benefit-cost analysis for multi-modal decision making using detailed zone-to-zone trip data output from travel-demand models for the I-15 corridor in Salt Lake City is presented. The analysis was conducted at two levels: corridor and region-wide. The research suggests that, when major investments are to be evaluated, the analyst should be very cautious in performing corridor-level analyses when such a trip-based approach is used, because of significant effects on the evaluation caused by traffic diverted into (or out of) the corridor.