Using STEAM for Benefit-Cost Analysis of Transportation Alternatives

The Intermodal Surface Transportation Efficiency Act emphasizes assessment of multimodal alternatives and demand management strategies. This emphasis has increased the need for planners to provide good comparative information to decision makers with regard to proposed alternative transportation solutions. Benefit-cost analysis is a useful tool to compare the economic worth of alternatives and evaluate tradeoffs between economic benefits and nonmonetizable social and environmental impacts. FHWA has developed a new tool for benefit-cost analysis called the Surface Transportation Efficiency Analysis Model (STEAM). The software is based on the principles of economic analysis and allows development of monetized impact estimates for a wide range of transportation investments and policies, including major capital projects, pricing, and travel demand management. Impact measures are monetized to the extent feasible, and quantitative estimates of natural resource usage (e.g., energy consumption) and environmental impact (e.g., pollutant emissions) are also provided. Decision makers can then use net monetary benefits (or costs) of alternatives as computed by STEAM to evaluate tradeoffs against nonmonetizable impacts. The software was applied in evaluation of corridor alternatives for the Central Freeway corridor in the hypothetical urban area of Any City, U.S.A.