To win the Indianapolis 500 is an American dream. The drivers share over $7 million for just one race. This year's winner, Rick Mears, has won the richest prize in motor sport four times. He describes what it is like to drive round the famous track at speeds approaching 240mph. "You work all year to try and win this one," he says. The programme features some of the great races and spectacular crashes. With classic archive material, it evokes the most dangerous and exciting age of US motor racing, the Board Speedways of the 1920s. In these high-banked ovals, built of wooden planks, drivers of some of the earliest single-seaters, the Millers, risked all in pursuit of riches and the American National Championship.