is an oval track less than one mile (1.6 km) long, with the majority being 0.5 miles (0.8 km) or shorter. Drivers seeking careers in oval track racing generally serve their apprenticeship on short tracks before moving up to series which compete on larger tracks. Due to their short length and fast action, these tracks are often nicknamed "bullrings". Professional-level NASCAR races on short tracks usually use a 500-lap or 400-lap distance. Short tracks in many cases have lights installed and routinely host night races. The short ovals still form the backbone of NASCAR in the feeder series. Three race tracks of this type are also represented in the Cup: Bristol, Martinsville and Richmond. At the request of some fans on social media, there are plans to hold more races on this oval type in the future. Tracks with potential for future cup races are the Iowa Speedway built in 2006, the Nashville Fairgrounds Speedway used until 1984 in the Cup, and the Memphis Motorsports Park, which had races of the Busch Series back then until the 2000s. The Auto Club Speedway is to be converted from a 2-mile super speedway to a 1/2 mile short track in 2023. Mile oval Synonymous with the name, a 1-mile (1.61 km) oval is a popular and common length for oval track racing. The exact measurements, however, can vary by as much as a tenth of a mile and still fall into this category. Most mile ovals are relatively flat-banked, with Dover being a notable exception. Many 1-mile dirt ovals were used by Stock cars or Champcars before race tracks with dirt surfaces were removed from the racing calendar in the early 1970s. Many of these racetracks got the nickname "Fairgrounds” — for example Arizona State Fairgrounds, California State Fairgrounds and Michigan State Fairgrounds Speedway. The origin of these racetracks was in harness racing, which commonly used 1-mile tracks. Also, the oldest oval race track, the Milwaukee Mile was originally a race track for horse racing. In NASCAR, 1-mile oval tracks are among the intermediate tracks. IndyCar rated these tracks as short ovals, since IndyCar does not usually run on ovals shorter than 3/4-mile. The 1-mile ovals have lost a great deal of their former importance for oval racing. Most of the racetracks abandoned by NASCAR or IndyCar in the 2000s were of this type. These include the Chicago Motor Speedway and the