The course of the track is 3.7 miles (6.0 km) long. It is a seventeen-turn road course with long straights, several high-speed corners, and very technical slower corners….Sebring is renowned for its rough surface. The course still runs on old sections of World War II-era landing fields that were constructed of concrete sections with large seams. The transitions between sections are quite rough and often, sparks fly from the undercarriages of the cars as they traverse them. Much of the track has intentionally been left with its original concrete runway surface. The track surface has 3.0 miles (4.8 km) of asphalt and 0.7 miles (1.1 km) of concrete. Mario Andretti, a 3-time 12 Hours winner, said that one of the hardest parts about the original Sebring track was finding the track to begin with!