Peterbilt people wore trucker hats before trucker hats were cool. A division of truck giant PACCAR, Peterbilt has been associated with big rigs since 1939. Peterbilt manufactures commercial medium- and heavy-duty diesel trucks for the toughest of jobs, including long-haul, over-the-road trucking, regional trucking, refuse collection, off-highway construction, logging, and oilfield work. About 10% of the nation's semi-trailer tractors are made by Peterbilt. Peterbilt also offers a range of aftermarket support, from parts to roadside assistance and scheduled maintenance programs for both fleets and owner/operators. Trucks are assembled at plants in the US and Canada, and marketed in North America via 250 dealers.