Oregon Administrative Rules
Chapter 741 - DEPARTMENT OF TRANSPORTATION, RAIL DIVISION
Division 310 - SIDE CLEARANCES
Section 741-310-0040 - Bridges and Tunnels

(1) Except as provided in sections (2) and (3) of this rule, side clearance for bridges and tunnels is 8 feet as measured from centerline of track.

(2) Minimum side clearance in tunnels and through bridges may be decreased, above 14 feet 6 inches, to the extent defined by a half-circumference of a circle having a radius of 8 feet with its center at a point 14 feet 6 inches above top of rail directly over the centerline of track. This rule does not alter the 20 feet 9 inches overhead clearance requirement of OAR 741-305-0010.

(3) Except where walkways are used by employees engaged in switching, the minimum side clearance does not apply to the lower section of a bridge so long as no part of the structure falls inside an encroachment line drawn from a point 5 feet from centerline of track and level with top of rail, diagonally upward to a point 8 feet from centerline of track at a height 4 feet above top of rail.

(4) See Figure 310-3 for a diagram of minimum clearances for tunnels and through bridges. See Figure 310-4 for a diagram of minimum clearances for the lower section of bridges.