Social Impact Analysis of Various Road Capacity Expansion Options: A Case of Managed Highway Lanes

Managed lanes (MLs) offer public infrastructure owners a key policy lever for reducing the financial burden of road expansion while managing induced travel demand. ML's impact varies depending on the operational method adopted. Previous literature has focused on only one option's optimum toll estimation, operational strategies, or impacts at a time. In this study, we provide the first detailed network-wide comparisons of MLs that include travel time, vehicle-miles-traveled (VMT), general-travel cost, fuel consumption, and emissions. We embed a toll-choice model within a four-step travel demand model considering drivers' value of travel time (VOTT). The study uses existing high-occupancy-toll (HOT) lanes and the surrounding network in the Dallas-Fort-Worth, Texas, area as a case-study area. We find the following: (1) HOT lanes are the preferred option providing the highest travel-time savings; (2) the all-tolled option performs the best at the corridor level. It reduces corridor travel time by around 20%. However, lower traffic volume on tolled lanes generates lower overall network performance; (3) high-occupancy-vehicle (HOT) performs the worst and is similar to the do nothing option; and (4) both priced options, all-tolled and HOT, generate the smallest total emissions and fuel consumption.