What must parked vehicles without an emergency brake system use?

Parked vehicles that do not have an emergency brake system must use chocks to ensure they remain securely stationary. Chocks are devices that prevent a vehicle from rolling by blocking its wheels. This is particularly important for vehicles that may be parked on an incline or in a situation where any movement could cause a safety hazard.

Using chocks is a standard safety practice to mitigate the risk of unintended vehicle movement, especially in environments like airfields where heavy machinery and vehicles are common. This safety measure helps to protect personnel and property from accidents that could occur if a vehicle were to roll away.

While safety cones, parking barriers, and warning signs all serve important roles in safety management, they do not provide the same physical immobilization that chocks do for vehicles lacking an emergency braking system. Thus, chocks are the necessary tool in this context to ensure stability and safety.