Safety rules governing driving company vehicles and operating company equipment must meet certain safety criteria, i.e: back up alarms, turn signals, glass condition, lights, brakes, and rollover protection structures (ROPS).
When working on an off-road project, it is suggested that you develop a plan to identify safe routes, traffic directions, and adequate signage.
The vehicle regulations are found in WAC 296-155.600-630 Part M & 155.950 Part V