Benefit-Cost Module (BC). The fourth module of TREDIS presents benefit/cost analysis of the project. It gathers information from TREDIS-TC and TREDIS-EA and organizes them in terms of various economic impact and economic benefit measures.

The benefit/cost module distinguishes between impacts on income and business sales (as used by TREDIS-EA) from the economic value of other social benefits that do not directly affect the flow of dollars in the economy. This latter category includes household value of travel time savings and increase in consumer surplus from induced travel. TREDIS-BC then separates these elements of travel efficiency, cost savings, productivity and social benefit measures (including regional income growth from TREDIS-EA). These are each compared with the net present value of costs to determine benefit/cost ratios from the differing perspectives of federal, state and local agencies.

Results. The benefit-cost report provides a summary of total project economic impact, cost and benefit. It also shows net benefit-cost and benefit/cost ratios. The components of these different measures are also shown. Benefit-cost results are shown in terms of on four different ways of measuring benefits: (1) transport system efficiency, (2) transport user cost savings, (3) total transport user benefit, (4) total social benefit, and (5) regional income benefit. All ratios are shown calculated on the basis of a discounted net present value of the benefit and cost streams, and are represented in terms of both national and local/state perspectives. (See example shown below.)