Regional traffic operation and vehicle emission impact assessment of lane management policies

Managed lanes are expected to reduce congestion and, potentially, vehicle emissions. Usually, planning agencies select lane management strategies first and foremost to improve regional mobility. Furthermore, transportation projects are regulated by the Clean Air Act towards the overall regional emission levels and project-level (or corridor-level) pollutant concentrations. The present study aimed to develop and implement an optimal integrated transportation and emissions modeling platform to evaluate regional vehicle emission and pollutant dispersion impacts and their significance for adding a managed lane facility to the roadway network. The case study examined the Loop 375-Border Highway West toll project in El Paso, Texas, under five proposed lane management strategies. Results confirmed the addition of a priced facility can provide congestion relief at the corridor level and cause some rerouting in other parts of the region. However, they do not appear to substantially reduce regional greenhouse gases and criteria pollutant emissions. The findings of the current study provide further insight within a regional context into selecting a transportation project and its true emission savings and air quality benefits.