A traction control system attempts to maintain an automobile’s traction with the ground. Traction can be lost in many different driving conditions, so a traction control system is operated automatically by an onboard computer. It typically will function by sensing a loss of traction and cutting power to the engine to restore the appropriate wheel speeds. While losing traction with the ground can be dangerous, many performance-oriented drivers prefer to disable a car’s traction control system. Anti-lock brakes offer traction control during braking.
A traction control system works by sensing when wheels are moving too fast for the car itself. When electronic sensors indicate that traction is being lost, an onboard computer signals for the engine to cut power. This can be accomplished in a variety of ways, including restricting air to the engine or preventing spark plugs from firing. Since the system is controlled by a computer, it can respond very quickly.
Losing traction with the ground can be particularly dangerous for rear-wheel-drive vehicles during cornering. Sharp cornering places a great deal of force on rear tires; if the driver applies too much throttle during cornering, the tires can break traction, and the car will start to spin. If the driver doesn’t correct the spin with the proper steering maneuvers, he could lose control of the vehicle entirely. This risk is exacerbated when roads are wet or tires are excessively worn.
Many automobiles allow the driver to disable the traction control system. While the system can increase the safety of an automobile, many performance enthusiasts prefer to drive without traction control. They claim that a traction control system unnecessarily hinders the power and handling characteristics of a vehicle. Traction control can be especially troublesome in off-road racing, which requires cars to break traction with the ground nearly constantly. For this reason, high-performance vehicles seldom use traction control in racing situations.
An analogous safety feature to traction control is anti-lock brakes, which attempt to maintain traction with the road during braking, rather than accelerating. Cars that try to stop too fast will tend to slide because they have too much momentum. While locked tires will cause a car to stop quickly, they also prevent the driver from steering during the period of braking. Anti-lock brakes sense when tires are locking and then relax the brakes until the wheels are rolling again. When the wheels roll with the ground, the driver can maintain the ability to steer the car until it stops.