Truck racing is a form of motor racing which involves modified versions of heavy tractor units on racing circuits. The sport started in Europe over twenty five years ago and enjoyed great success, but declined in the 1990s. However, in the last few years the profile of truck racing has increased, and currently over 30 teams regularly compete. The sporting regulations came under the control of the Fédération Internationale de l'Automobile (FIA) later, to ensure that the vehicles conform to the layout and original style of the truck, whilst defining the safety standards required to race.