Light communication systems have some advantages over sound-based systems. Even when wearing hearing protection equipment like earplugs, workers can still see and interpret signals from light communication systems.

    Moreover, the clarity of common color systems, such as red for stop and green for go, transcends language barriers, which limits miscommunications in the workplace.

    Light communication systems tell people around the loading dock, inside a trailer or alongside a truck exactly what is happening.

    A green light inside or near the entrance to the trailer can tell forklift operators that it's safe to enter the trailer for loading or unloading, while a red light outside tells the truck driver to remain parked.

    When all the work is completed and it's time for the truck to pull away from the dock, the lights switch; a red light says it's not safe to approach the trailer, while a green one indicates the driver can safely move forward.

    In other types of systems, a blue light might mean someone or something is moving inside the trailer, forewarning everyone involved to be cautious when approaching the trailer.