The following description was taken from Safe Reversing and Spotting Practices by WorkSafe New Zealand:

This guide offers practical advice on how you can manage the risks of reversing vehicles and mobile plant.
This guide is written for:
– PCBUs (persons conducting a business or undertaking) who manage a work site where there may be reversing vehicles or mobile plant
– PCBUs whose workers work on or near vehicles or mobile plant (at a site they manage, or any other site)
– workers that are involved with directing or operating reversing vehicles or mobile plant.

Under the Health and Safety at Work Act 2015 (HSWA) PCBUs have a duty to make sure the health and safety of workers, contractors, visitors and members of the public are not put at risk as a result of the work that they do. This includes a duty to make sure people are safe around vehicles and mobile plant while at work. Workers also have a duty to take reasonable care for their own health and safety and make sure their actions do not cause harm to others.