Final answer:
A haul truck driver requires a safety spotter and signaling devices when dumping material at a high dump point or near the crest of the dump.
Step-by-step explanation:
When dumping material at a dump site higher than three meters in height or within three meters of the dump's crest, a haul truck driver is obliged to take specific safety precautions.
Having a safety spotter or a way to get in touch with one is one need to make sure that the dumping is done securely and without any mishaps.
Having appropriate signaling equipment, like lights or flags, to alert other cars and workers to the truck's presence and possible hazards, is another requirement.