U.S. automobile race.
It has been held annually since 1911 at the Indianapolis Motor Speedway, a 2.5-mi (4-km) asphalt oval with banked quarter-mile turns. The "Indy 500" is a 500-mi (805-km) race for top international competitors using specially designed Formula One cars (open-wheel, open-cockpit, rear-engine vehicles). Traditionally held on or near Memorial Day, the race is one of the most prestigious on the international racing circuit, drawing large crowds (about 300,000) and offering substantial prizes (more than $1.5 million).