A wheel chock is a wedge placed against a trailer or truck tyre to stop the vehicle rolling, used at loading docks so the trailer cannot move while a forklift drives in and out.
OSHA 1910.178 requires the brakes of highway trucks to be set and wheel chocks placed under the rear wheels to prevent them rolling while forklifts board them, and 1910.26 requires measures to keep the transport vehicle from moving while employees are on a dockboard. Chocks are the simplest way to meet that, and they also serve as the fallback when a mechanical vehicle restraint cannot engage a trailer.
Chocks rely on people. They can be forgotten, placed on the wrong wheel, lost, or pushed aside by a trailer pulled away by a driver who did not know loading was still under way. Sites reduce that risk with clear ownership of who places and removes chocks, chocks kept on a chain or holder at each door, signal lights or a key-and-lock procedure that ties the truck driver’s departure to chock removal, and sensor-equipped chocks that report placement to dock lights. The loading dock forklift safety guide covers trailer creep and early departure.