What is the main purpose of a vehicle's parking brake system?

The primary purpose of a vehicle's parking brake system is to prevent the vehicle from rolling while stationary. This is particularly important in situations where the vehicle is parked on an incline or uneven surface. The parking brake, also known as the handbrake or emergency brake, engages the rear wheels (or sometimes all wheels) to hold the vehicle securely in place, ensuring it does not move accidentally.

While some may think of the parking brake as providing additional stopping power, its main function is related to safety during stationary situations rather than enhancing the vehicle's braking capabilities in motion. Parking brakes are designed with the intention of securing the vehicle when parked, not to serve as a primary braking system or to support anti-lock braking systems (ABS). Additionally, the parking brake does not directly lessen wear on the main brake system; rather, it operates independently to maintain the vehicle's safety and stability when it is not being driven.