Reducing Fuel Consumption and Greenhouse Gas Emissions of Medium- and Heavy-Duty Vehicles, Phase Two: Final Report

Medium- and heavy-duty trucks, motor coaches, and transit buses - collectively, "e;medium- and heavy-duty vehicles"e;, or MHDVs - are used in every sector of the economy.

The fuel consumption and greenhouse gas emissions of MHDVs have become a focus of legislative and regulatory action in the past few years.

This study is a follow-on to the National Research Council's 2010 report, Technologies and Approaches to Reducing the Fuel Consumption of Medium-and Heavy-Duty Vehicles.

That report provided a series of findings and recommendations on the development of regulations for reducing fuel consumption of MHDVs.On September 15, 2011, NHTSA and EPA finalized joint Phase I rules to establish a comprehensive Heavy-Duty National Program to reduce greenhouse gas emissions and fuel consumption for on-road medium- and heavy-duty vehicles.

As NHTSA and EPA began working on a second round of standards, the National Academies issued another report, Reducing the Fuel Consumption and Greenhouse Gas Emissions of Medium- and Heavy-Duty Vehicles, Phase Two: First Report, providing recommendations for the Phase II standards.

This third and final report focuses on a possible third phase of regulations to be promulgated by these agencies in the next decade.