Endurance racing (motorsport) these classes continued to embrace the endurance format. Multiple drivers per car was an early adaptation as the rigors of endurance racing quickly overcome the abilities of most racing drivers to compete solo, although solo attempts on 24 hour races like Le Mans would continue into the 1950s. The various endurance formats were appealing to manufacturers, not only as alternatives to the expense of Grand Prix racing, but also because of its increased relevance to road going models. In automobile endurance racing, three events have come to form a Triple Crown. They are considered three of the most challenging endurance
Oval track racing start-finish straight to the pit lane with two 180 degree turns, resulting in a concentric 1/4-mile oval layout. The 1/4-mile layout became a popular venue for legends car racing. The name "legends oval" was derived from this use. They have also seen use with go-karts, short track stock cars, and other lower disciplines. This idea was adopted by numerous tracks including Texas Motor Speedway, Atlanta Motor Speedway, Kentucky Speedway, Las Vegas Motor Speedway, and Iowa Speedway which has a 1/8 mile version. Perhaps the most unusual concentric oval facility is Dover Speedway-Dover Downs. The one-mile oval track encompasses a 0.625-mile