This report evaluates the effects of adopting California heavy-duty vehicle emissions control programs in 13 states and the District of Columbia. These programs include the Advanced Clean Trucks (ACT) regulation, the Heavy-Duty Omnibus regulation, and full implementation of the California HD Vehicle Greenhouse Gas (GHG) Phase 2 regulation, including requirements on tractor-trailers.
Since California’s emissions control programs exceed the requirements of federal programs, the Clean Air Act allows other U.S. states to join the more stringent California programs provided the U.S. Environmental Protection Agency grants California a waiver from federal requirements and states delay implementation by two model years.
This analysis adopts the methodology developed by the California Resources Board to estimate the benefits of its own programs. The methodology is applied to other U.S. states taking vehicle population and activity projections generated from the U.S. EPA MOVES3 model at the county scale. Since California’s methodology limits its benefits accounting to electric vehicles (EVs) that do not migrate out of state and to the marginal increase in EVs from the ACT, the report includes a comparative analysis showing the benefits with these additional vehicles. These two approaches are described, respectively, as the ‘ACT Only EVs’ and the ‘All EVs’ approaches in the report.