Abstract:
Benefit-cost (B/C) analysis is a useful tool to compare the economic worth of transportation alternatives across modes. However, the application of tools such as MicroBENCOST, IDAS, and STEAM for B/C analysis in metropolitan areas raises several important technical issues that can significantly affect the results of the analysis. Several issues relate to use of four-step travel model outputs in estimation of benefits. Use of an inappropriate "No Build" base for comparison can exaggerate benefit estimates, as can a lack of consideration of the impact of induced travel. Link-level analysis can overestimate benefits from travel time savings, and at the system level, only trip-based analysis can adequately address issues relating to the "constant travel time budget" theory. Finally, use of congested speeds output by traffic assignment models can exaggerate travel time savings. These issues and their implications in metropolitan transportation decision making are discussed.
Supplemental Notes:
This paper appears in Transportation Research Record No. 1685, Transportation Planning, Programming, Public Participation, and Land Use.
