Of all the impacts of peak oil, the clearest are those on transportation, particularly use of the automobile. Transportation accounts for almost 40 percent of the energy used in Oregon, and 95 percent of the energy used for transportation is oil. With rare exceptions, cars, trucks, buses, planes, boats and trains all use petroleum-based fuels, and about 85 percent of all petroleum is used for transportation.

Peak oil has direct, major implications for movement of freight, movement of people and migration of populations into or out of an area. These, in turn, will have secondary but major impacts on land use patterns. Cheap transportation fuel after World War II strongly influenced land use patterns and roads, and buildings and roads are durable features of the landscape that are difficult and slow to change.