(1) You must provide a pedestrian overpass covering the full width of a passageway if one of these conditions exists:

(a) The working strand of a conveyor crosses within three feet of floor level.

(b) Workers must step over the strand and trough at or below floor level.

(2) You must provide a pedestrian overpass where workers cannot pass under the conveyor safely. The sides of the crossing platform must have standard railings if one of the following exists:

(a) The overpass is more than four feet high.

(b) The conveyor feeds a dangerous machine such as saws, chippers, hogs, or galvanizing tanks.