If you suspect a load in the back of a vehicle may shift during transit, you should:

Securing the load with ropes and straps is the most appropriate action to take if there is a suspicion that a load in the back of a vehicle may shift during transit. This proactive measure ensures that the load remains stable and securely in place, minimizing the risk of accidents or damage to both the load and the vehicle. Properly securing loads is a fundamental safety practice in transportation, as it protects the driver, other road users, and the integrity of the cargo.

While driving slowly may seem like a reasonable strategy to prevent movement, it doesn't address the fundamental issue of securing the load, which remains at risk of shifting regardless of speed. Informing a supervisor can be beneficial, but it does not provide an immediate solution to the problem. Refusing to drive the vehicle is also an option, yet it may not be necessary if the load can be properly secured. Ultimately, taking steps to secure the load directly addresses the concern and enhances safety during transit.