Several regions with large vehicle markets are developing regulatory programs to reduce the fuel consumption and greenhouse gas emissions of heavy-duty vehicles. At the same time, manufacturers increasingly are developing global product platforms for the heavy-duty market. This offers an opportunity to accelerate the development and adoption of fuel efficiency technologies. Regulators can facilitate this outcome by coordinating the design of fuel efficiency and greenhouse gas emissions reduction programs across regions. This report compares key features of the regulatory programs in place or under development and explores the prospects for aligning them.