The terms parking brake and emergency brake are used interchangeably in the automotive world to refer to a purely mechanical brake system which can be actuated in the event of hydraulic failure, or used to secure a car when the motor is off and the car is parked. The term used depends on the scenario. In an emergency situation, the emergency or e-brake can be used to stop a car safely. In daily use, the parking brake is used as a safety measure to prevent runaways. Like the rest of the brake system, the parking brake should be regularly inspected to ensure that it is performing properly.

The parking brake consists of a series of steel cables which run from the rear brakes to a pedal or lever by the seat of the driver. When the driver activates the parking brake, the cables pull taut, bringing the brake pads into contact with the surface of the brake and stopping the car, or preventing it from moving. Because the cables are attached to a ratcheting lever or pedal, when the driver removes the hand or foot used to activate the parking brake, the brake will still hold. In order to remove the brake, the driver must take another action, such as pressing a button and lowering the lever.

Although the parking brake is attached to the regular brakes of the car, it is independent of the hydraulic braking system connected to the brake pedal. In an emergency situation where the hydraulic brakes fail, the driver can still stop the car using the emergency brake. It is recommended that a driver downshift before applying the emergency brake, as this will slow the car significantly, and reduce the grabbing feeling that accompanies high speed use of the emergency brake. In addition to being more comfortable for driver and passengers, this is also a safety measure, as if the car is traveling at a high rate of speed, it can fishtail or spin out when the emergency brake is applied.

When parking a car, it is important to set the parking brake, so that if the car slips into gear, it will not roll. This applies to vehicles with automatic transmissions as well. In addition, drivers who are parking on a hill facing downhill should turn their wheels toward the curb or side of the road, so that if the car slips into gear and the brake slips, the car will roll off the road, rather than into it. When facing uphill with a curb present, the wheels should face into the street, so that the car will roll back slightly and bump into the curb if it rolls. If there is not a curb, the wheels should face towards the side of the road.