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 .
The decision to run horses counterclockwise in the US dates to the American Revolution era. In 1780, the first circular US race track was established by William Whitley near his home in Lincoln County, Kentucky. A staunch supporter of the Revolution, Whitley insisted that horses race counterclockwise, as opposed to clockwise as was the custom at the time in England.
In IAAF (International Association of Athletics Federations)
IAAF Rule 163.1 states:
The direction of running shall be left-hand inside
there are explanations for counterclockwise races but none is formal:
- International agreement stipulating the direction related to the setting up of equipment to time the finishes and judge dead-heats (close finishes). If all running events are run in the same direction it means that it simplifies the process of setting up the equipment across different venues.
- Every NASCAR oval track has only left turns, because the drivers sit on that side of the car. The drivers generally try to keep to the inside of the track (because it is a shorter distance around the track) So by making all left turns, the drivers can better see what is going on around them.
- Safety reasons, keeps the driver away from the out side wall (guardrail in the old days).
- that spectator will percieve the runners as moving left to right - the same direction our eyes move when we read.
- the human body is slightly heavier than the right because of the heart and when running anticlockwise, the body would tend to very slightly incline towards the left, which could be an advantage while running anticlockwise
- Most people are right hand/leg dominant.Moving counterclockwise we have a better control and move faster.
Read more: wiki.answers.com, answers.yahoo.com
You can look on different interesting paper that tool about the directions types in generally and not only in sport - straightdope