What is the purpose of a commercial vehicle's emergency brake?

The purpose of a commercial vehicle's emergency brake, often referred to as the parking brake, is primarily to hold the vehicle in place when parked. This is essential for safety, especially when the vehicle is on a slope or an incline where there is a risk of rolling away. The emergency brake engages a mechanism that applies pressure to the vehicle's wheels, preventing movement until the brake is released. This is a critical feature that ensures stability and safety for both the vehicle and its surrounding environment when it is not in motion.

In contrast, the emergency brake is not intended for stopping the vehicle during normal driving, assisting in driving uphill, or primarily reducing wear on the main brakes. While it may serve as a backup in the event of a failure of the primary braking system, its fundamental function is to secure the vehicle in a stopped position when parked.