When working underneath a vehicle, which safety measure is essential?

Ensuring proper wheel chocks are used is crucial when working underneath a vehicle because they provide a vital safety measure to prevent the vehicle from rolling. When a vehicle is raised, whether on a jack or in a maintenance position, it is essential to secure the wheels to avoid any movement that could lead to serious injury or even fatal accidents. Wheel chocks create a physical barrier against unintended motion, allowing the technician to focus on the work at hand without the added worry of the vehicle rolling away.

Using a floor jack only or working without a jack stand is dangerous as it does not provide stable, long-term support for the vehicle and could lead to it collapsing. Additionally, working without safety glasses exposes the technician to potential eye hazards from falling debris or fluids. The use of proper wheel chocks fundamentally ensures that the vehicle stays securely in place, making it a non-negotiable element of safety protocol in any automotive maintenance scenario.