The Indianapolis Motor Speedway oval has four distinct turns. The 2.5-mile oval is nearly rectangular rather than a smooth, circular oval, with Turns 1 through 4 connected by two long straightaways and two shorter “chutes.” Each turn is geometrically identical and banked at roughly 9 degrees 12 minutes.
The layout dates to the speedway’s construction in 1909 and has remained essentially unchanged. Each turn measures one-quarter mile, while the straight sections complete the famous 2.5-mile lap. Drivers race counterclockwise, entering Turn 1 after the front straight and completing the lap by exiting Turn 4 onto the main straight.
A common mix-up comes from Indianapolis also having several road-course configurations. Those layouts use additional infield corners and therefore have more than four turns. The four-turn answer applies specifically to the historic oval used for the Indianapolis 500, not to the modern Grand Prix road course.