What should the driver/operator do if he or she loses sight of the spotter during backing?

Answer: D — Stop and set the parking brake

When a driver or operator loses sight of the spotter during a backing maneuver, the safest course of action is to stop and set the parking brake. This decision prioritizes safety by preventing any potential accidents that could occur if the vehicle continues to reverse without guidance. By halting the vehicle immediately, the operator ensures that they do not inadvertently back into an obstacle, another vehicle, or personnel who may be in the vicinity. Setting the parking brake further ensures that the apparatus remains stationary, preventing it from rolling unintentionally. This is critical in maintaining control of the equipment and ensuring that all operators and spotters can safely communicate and re-establish visual contact before proceeding. In contrast, continuing to back up or sounding the horn without being able to see the spotter could lead to dangerous situations, as the driver would be operating without essential visual feedback. Calling for additional spotters could be a proactive measure, but it doesn’t address the immediate need to stop to promote safety in the moment. Therefore, stopping and securing the vehicle is the appropriate and safest action to take.