30 CFR 56.9200 - Transporting persons.
Persons shall not be transported -
(b) In beds of mobile equipment or railcars, unless -
(1) Provisions are made for secure travel, and
(2) Means are taken to prevent accidental unloading if the equipment is provided with unloading devices;
(d) Outside cabs, equipment operators' stations, and beds of mobile equipment, except when necessary for maintenance, testing, or training purposes, and provisions are made for secure travel. This provision does not apply to rail equipment.
(e) Between cars of trains, on the leading end of trains, on the leading end of a single railcar, or in other locations on trains that expose persons to hazards from train movement.
(1) This paragraph does not apply to car droppers if they are secured with safety belts and lines which prevent them from falling off the work platform.
(2) Brakemen and trainmen are prohibited from riding between cars of moving trains, but may ride on the leading end of trains or other locations when necessary to perform their duties;
(f) To and from work areas in overcrowded mobile equipment;
(g) In mobile equipment with materials or equipment unless the items are secured or are small and can be carried safely by hand without creating a hazard to persons; or
(h) On conveyors unless the conveyors are designed to provide for their safe transportation.