Hill-holder

Any device that prevents a car from rolling backward on a hill when the brake pedal is released can be called a hill holder. The earliest hill holders were used in horse-drawn carriages and early horseless carriages. They were often home-made or made by a local blacksmith. These early hill holders were little more than a heavy iron weight with a spike or other sharp end that could be quickly dropped behind a wheel when the need arose, preventing the vehicle from rolling backward.