Motor Vehicles and Mechanized Equipment

All vehicles in use shall be checked at the beginning of each shift to ensure that all parts, equipment, and accessories that affect safe operation are in proper operating condition and free from defects. All defects shall be corrected before the vehicle is placed in service. 1926.601(b)(14)

No employer shall use any motor vehicle, earthmoving, or compacting equipment having an obstructed view to the rear unless:

• The vehicle has a reverse signal alarm distinguishable from the surrounding noise level, or the vehicle is backed up only when an observer signals that it is safe to do so. 1926.601(b)(4)(i) through (ii) and 602(a)(9)(i) through (ii)
• Heavy machinery, equipment, or parts thereof that are suspended or held aloft shall be substantially blocked to prevent falling or shifting before employees are permitted to work under or between them. 1926.600(a)(3)(i)