The Daytona 500 was founded in 1959 as a 500-mile race, and while this is the final distance of the race in most cases, there have been some exceptions, including during the gas crisis of 1974, when the race was shortened to 450 miles. There have been four other instances of shorter races throughout the race's multi-decade history. NASCAR officials shortened the race due to inclement weather in 1965 (332.5 miles), 1966 (495 miles), 2003 (272.5 miles) and 2009 (380 miles).
The 500-mile length has become so synonymous with the event that it determined the race's official name. In fact, the Daytona 500 has only been officially known by that name since 1961. The track itself is 2.5 miles long, and it requires 200 laps to complete.
While the race has been shorter than 500 miles, it has also been longer. In 2004, NASCAR and race officials introduced a rule that makes it possible for the race to extend beyond the standard 500 laps. Though several of the races after this rule did run exactly the standard 500 miles, the 2015 edition, which was won by Joey Logano, was 507.5 miles long.