Anticipating Roadway Expansion and Tolling Impacts: Toolkit for Abstracted Networks

Abstract

Transportation investments are nearing $1,000 per capita annually in the USA, and the Highway Trust Fund has been depleted. Such significant investments and budget-constrained contexts demand careful decision-making and thoughtful cost-benefit analyses. A project evaluation toolkit has been developed for comprehensive assessment of network expansion and pricing projects with only project expenditures, link attributes, and traffic counts as required inputs. The toolkit uses a self-contained travel demand model to predict future and alternative scenario traffic volumes, speeds, crash counts, emissions, and toll revenues while providing project-summary measures, including net present value and benefit-cost ratios. The toolkit seeks to provide early assessment of major project plans along abstracted networks, using hundreds of coded links (rather than thousands), providing results in a matter of minutes (rather than days). This paper describes the model and develops two case-study sites, each with several alternative scenarios. The first examines capacity expansion projects along a highly congested link on the periphery of Austin, Texas, while the second focuses on strategies to reduce traffic in central Austin through tolling and capacity-reduction projects. Toolkit results show which projects merit further consideration by summarizing and monetizing impacts across scenarios.