How does traction control a vehicle?

Traction controls a vehicle by determining the amount of force that can be applied between the surface of a tire and the road. Without traction, the direction or speed of a vehicle would be impossible to control.

The force produced by a vehicle's engine is known as torque. Transmission and differential gears serve to multiply the torque produced by an engine and to distribute force to the wheels, where it is used to produce directional motion. Traction is a measure of friction that exists between a vehicle's tires and the road. Without traction, a phenomena known as wheel slip occurs, which results in wheel spin that is unable to produce directional motion. Tire traction is also needed in order to steer a vehicle.

Some vehicles are equipped with a system known as traction control, which limits tire slip and improves handling and acceleration on slippery surfaces. This system utilizes sensors to measure differences in the rotational speed of each wheel. When engaged, more torque from the engine is transferred to the wheels that have the most traction. While traction control is able to make better use of existing traction, it is unable to create traction or to improve the level of traction available.