Grass track racing

Dirt track racing is a type of auto racing performed on clay or dirt surfaced oval tracks. It started in the United States before World War I and became widespread during the 1920s and 1930s. Two different types of race cars dominated—open wheel racers in the Northeast and West and in the South. While open wheel race cars are purpose-built racing vehicles, stock cars (also known as fendered cars) can be either purpose-built race cars or street vehicles that have been modified to varying degrees.

Dirt track racing is the single most common form of auto racing in the United States. There are hundreds of local and regional racetracks throughout the nation; some estimates range as high as 1500. The sport is also popular in Australia, New Zealand, Canada, and the United Kingdom.

The track surface may be composed of any soil, but most racers prefer a track with a clay base. The curation of a racetrack is a long and complex job and requires hours of work. Typically the machines for track curation include a grader, cultivator, roller and water truck however this varies at different dirt tracks around the world. Typically the track is graded and 'dug up' after the racing is finished and then it is watered with a water truck. It may be then broken down with a cultivator or rolled. These steps are repeated however many times necessary and do vary according to climate, location and soil composition.

Nearly all tracks are oval and less than 1-mile (1.6 km) in length with most being ½ mile (804 m) or less. The most common increments in the U.S. are ½ mile, ⅜ mile (603 m), ⅓ mile (536 m), ¼ mile (402 m), and ⅛ mile (201 m). With the longer tracks, the race cars achieve higher speeds up to 160 mph (257kmh) and the intervals between cars increase. This decreases the chance of crashes but increases the damage and chance of injury when cars do crash.

In Great Britain the oval tracks are normally on grass with lengths of 400 meters (¼ mile) to 800 meters (½ mile). The races consist of several four lap qualifying heats that eliminate slower drivers. Then there is a final race featuring the fastest competitors.

In mainland Europe, long tracks can be grass, sand or cinder, and can be up to 1-kilometer (0.62 mi) long.

Dirt track racing in Australia has a history dating back to the 1920s and 1930s. Most oval track speedways are similar to those in the USA for car racing such as sprint cars, speedcars (midgets) and sedans, with most tracks generally around ¼ mile (402 m) to ⅓ mile (536 m) in length. Most tracks have a clay surface, though some use dolomite, dolomite and clay mix or even sand and clay mix. During the 1970s and early 1980s, a small number of tracks were paved with asphalt, though this phase only lasted about a decade and all tracks paved over eventually reverted to their former surfaces.

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