A 497 page document containing the proposed regulations for limiting greenhouse gas emissions from medium and heavy duty motor vehicles is now available in the Federal Register. Proposed by the Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA), the regulations are designed to transition the United States to a "new generation of clean vehicles." Vehicles proposed for regulation include combination tractors, heavy-duty pickup trucks and vans, vocational vehicles, and gasoline and diesel heavy-duty engines.
The summary at the beginning of the document mentions that NHTSA's proposed fuel standards for these vehicles would be voluntary in 2014 and 2015 but mandatory for new models in 2016. EPA's proposed gas emission standards would begin with 2014 models.
