Dirt track racing is the single most common form of auto racing in the United States. According to the National Speedway Directory there are over 700 dirt oval tracks in operation in the United States.
The composition of the dirt on tracks has an effect on the amount of grip available. On many tracks people will find clay is used with a specific mixture of dirt. Tracks are sometimes banked in the turns and on the straights. This banking is utilized primarily to allow vehicles to carry more speed through the corners. However, some tracks prefer less banked turns. Each track surface will most often be different in one way or another.
The Wall Street Journal noted that the success of local dirt track racing is a good economic indicator. Small businesses sponsor local grass-roots racing as part of their marketing budget. Many of the fans in the grandstands attend to support relatives and they consider the costs of attending the races to be modest.