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 and dirt track motorcycles. Oval track racing is the predominant form of auto racing in the United States. According to the 2013 National Speedway Directory, the total number of oval tracks, drag strips and road courses in the United States is 1,262, with 901 of those being oval tracks and 683 of those being dirt tracks. Among the most famous oval tracks in North America are the Indianapolis Motor Speedway and Daytona International Speedway. Notable ovals in other countries include Rafaela in Argentina, Mexico City in Mexico, Motegi in Japan, Lausitzring in Germany, the Calder Park Thunderdome in Australia, Brooklands