Sources for Assessing Benefits of High-Occupancy-Toll Lane Projects

Transportation agencies are becoming increasingly interested in High Occupancy Toll (HOT) lanes as a strategy to address urban highway congestion. However, assessing the financial feasibility and public benefits of HOT lane projects requires additional information (e.g., detailed average vehicle occupancies, HOT lane capacity, and travel demand elasticity) than what is typically collected to assess traditional capacity expansion projects. The California Department of Transportation (Caltrans) is currently updating its Cal-B/C benefit-cost model. As part of the update, the project team has identified and researched several topics that are relevant to assessing the benefits of HOT lanes. These topics include enforcement, travel time, safety, vehicle operating costs and emissions, and project costs and revenue. While not intended to provide a comprehensive framework for benefit assessment, this paper offers transportation practitioners with a list of references and issues to consider as they calculate the benefits of HOT lane projects.