What is the most important hand signal you should agree on with a helper?

The most important hand signal to agree on with a helper is to signal "Stop." This signal is crucial for ensuring safety during operations that involve teamwork, especially in situations where visibility may be limited or where there may be potential hazards. A clear and unified signal to stop helps prevent accidents and ensures that all parties can react quickly to any situation that demands immediate attention.

While other signals, such as "Go," "Slow down," and "Turn left," are important for coordination and guidance, the signal to stop is the one that directly addresses safety by ensuring that all activities cease immediately. This can be especially vital in settings like loading and unloading, where moving equipment and pedestrians may be at risk. By prioritizing the stop signal, both the driver and the helper have a system in place to pause operations when necessary, ultimately promoting a safer working environment.