What Factors Affect a Car's Stopping Distance?

Factors that affect a car's stopping distance include the composition and condition of its tires; the quality of its suspension and braking systems, and the weather. Road conditions, the driver's level of experience and an anti-lock braking system installed in a car also have an impact on its stopping distance.

Tire traction and the traction coefficient play a major role in determining the distance that a car travels once its driver applies the brakes. Increasing the traction coefficient shortens the braking distance. Tires with worn treads tend to skid, which decreases the traction coefficient and lengthens the braking distance. High-performance tires generally produce high traction coefficients. Snowy, wet and icy roads also decrease traction coefficients.

Worn springs, shocks, brake pads, drums and rotors allow a car to continue moving forward when heavy braking occurs. The more the weight of a car continues forward movement during braking, the longer the stopping distance. A driver's ability to handle poor and unexpected road and vehicle conditions makes a difference in how long it takes to stop a vehicle.