The U.S. Department of Energy (DOE) Office of Heavy Vehicle Technologies (OHVT) was created in March 1996 to address the public-interest transportation-energy aspects of a set of customers who at that time had been largely unrecognized, namely, the manufacturers, suppliers, and users of heavy transport vehicles (trucks, buses, rail, and inland marine). Previously, the DOE had focused its attention on meeting the needs of the personal-transport-vehicle customer (automobile manufacturers, suppliers, and users). Those of us who were of driving age at the time of the 1973 oil embargo and the 1979 oil price escalation vividly recall the inconvenience and irritation of having to wait in long lines for gasoline to fuel our cars. However, most of us, other than professional truck owners or drivers, were unaware of the impacts that these disruptions in the fuel supply had on those whose livelihoods depend upon the transport of goods. Recognizing the importance of heavy vehicles to the national economic health, the DOE created OHVT with a mission to conduct, in collaboration with its industry partners and their suppliers, a customer-focused national program to research and develop technologies that will enable trucks and other heavy vehicles to be more energy-efficient and able to use alternative fuels while reducing emissions. The Office of Heavy Vehicle Technologies convened a workshop in April 1996 to elicit input from DOE's heavy vehicle industry customers, including truck and bus manufacturers, diesel-engine manufacturers, fuel producers, suppliers to these industries, and the trucking industry. The preparation of a ''technology roadmap'' was one of the key recommendations by this customer group. Therefore, the OHVT Technology Roadmap* was developed in 1996 as a first step in crafting a common vision for a government research and development (R and D) partnership in this increasingly important transportation sector. The approach used in developing the OHVT Technology Roadmap was to: formulate goals consistent with the U.S. Department of Energy Strategic Plan required by the Government Performance and Results Act (GPRA), assess the status of the technology, identify technical targets, identify barriers to achieving the technical targets, develop an approach to overcoming the barriers, and develop schedules and milestones. This structure was followed for three groups of truck classification: Class 7 and 8: large, on-highway trucks; Class 3-6: medium-duty trucks such as delivery vans; and Class 1 and 2: pickups, vans, and sport utility vehicles (SUVs).