Track surface
The track surface of a horse racing track refers to the material of which the track is made. There are three types of track surfaces used in modern horse racing. These are:
Turf, the most common track surface in Europe
Dirt, the most common track surface in the US
Artificial or Synthetic, the collective term for a number of proprietary man-made surfaces in use at a number of locations around the world.
The style of racing differs between surfaces, with dirt races tending to be faster than those on turf or artificial surfaces. Anecdotally, dirt racing is the more reliable, and thus more popular, medium for betting purposes. Weather conditions affect the speed of the different surfaces too, and grading systems have been developed to indicate the track condition (known as the "going" in the UK and Ireland).
Synthetic surfaces
Synthetic surfaces allow racing to take place in bad weather conditions, when it may otherwise be cancelled, and for this reason are sometimes referred to as All Weather surfaces. Manufacturers of synthetic racetrack surface materials promote the fact that synthetic tracks have drainage attributes that are better than natural surfaces. There is also some evidence to suggest that synthetic surfaces are safest in terms of equine welfare.