The Pros and Cons of Using the Change in Destination Choice Logsums as a Practical Measure of User Benefits

Abstract

The Metropolitan Transportation Commission carries out an extensive project performance assessment in support of regional planning efforts. For the 2017 regional transportation plan, various types of potential transportation investments were evaluated against qualitative and quantitative criteria. The quantitative metric was a benefit–cost ratio, in which a project’s expected annual benefits were compared with the project’s expected annualized cost. To quantify user benefits (one component of the total benefit estimate), agency staff used the difference in Project/No Project destination choice logsums generated by the region’s activity-based travel model. The destination choice models include, as covariates, mode choice logsums, which means the change in destination choice logsums estimates the change in consumer surplus across all destinations and all travel modes. This approach has long been advocated for in academia and was applied by the Federal Transit Administration for evaluating transit investments in the 2000s. This is the first time that it has been fully implemented in a large-scale, multi-modal application that informs investment decisions. This paper discusses the pros and cons of using this approach. The pros include consistency between simulated behavioral changes in the travel model and quantification of benefits, which cannot be achieved using typical measures of benefits such as travel time savings, as well as the ability to map changes in access across the region. The cons include issues related to the form and creation of alternatives in the mode choice model and the difficulty in explaining changes in logsums to non-technical audiences.