In stock car racing, the cars are based on production, consumer automobiles. In the U.S. the driver is positioned on the left-hand side of the car. By racing counter-clockwise, the driver enjoys a better field of view of the track through the turns and is farther away from the wall -- both increasing the overall safety. read more
Not all tracks are counter clockwise, The exceptions being the Australian version of NASCAR (AUSCAR) and horse racing is often run clockwise outside the US such as England(St Leger - wikipedia.), Continental Europe, Australia, and Hong Kong. also some of F1 races are clockwise like . read more
Oval racing has been going left since before NASCAR was around. Indianapolis Motor Speedway has always run their oval counter-clockwise and has been in use since 1909. This predates NASCAR. One reason for NASCAR to do so though, is that it's easier to position a left-hand drive car through a left turn than it is through a right hander. read more