In the U.S., more than 100 people are killed annually on construction sites because of heavy equipment accidents. A construction site is a busy area and all vehicles have blind spots. Hand signals are necessary for these reasons when using heavy equipment.
The main form of communication between heavy equipment operators and workers is hand signals. Clear communication between equipment operators and workers prevents accidents. Standard hand signals facilitate communication.
Constant visual contact between the operator and the signaller is necessary. Any dangers in the path of the vehicle must be communicated to the operator. The signaller is also responsible for warning workers on foot of the approaching vehicle.
Stop is communicated by the signaller raising his hand with his palm facing outward. When asking the operator to back up, the signaller moves his hand toward him in a repetitive motion. When communicating a change in direction, the signaller raises his left or right arm depending on the desired direction.