Mecca of U.S. automobile racing, the Indianapolis Motor Speed­way was initially surfaced in 1909 with a mixture of crushed stone and tar. However, the track soon began to disintegrate as speeds exceeded 70 miles an hour, and up to 20 cars competed in the longer events of 300 miles. To prevent further problems, more than 3 million bricks, grouted in cement, were installed on the 2-mile circuit in late 1909. It was not until the ’30s that the famed brickyard needed major resur­facing and the roughest stretches were paved with asphalt.

Since then, routine repairs keep the track in excellent condition. In 1988, the track again needed major resurfac­ing. The major recurring problem is reflective cracking. Reflective cracking was causing problems since the cars have a meager 2 inches of clearance. (Reflective cracking occurs when an existing crack in the concrete base is reflected through to a new surface.)