Illinois Administrative Code
Title 92 - TRANSPORTATION
Part 1500 - MINIMUM CLEARANCES APPLICABLE TO TRACKS, STRUCTURES, FIXTURES AND OTHER APPURTENANCES OF RAILROADS
Subpart C - STRUCTURAL CLEARANCES
Section 1500.160 - Bridges

a) Railroad Bridges Supporting Main Tracks or Subsidiary Freight Tracks. The clearances of all railroad bridges supporting main tracks or subsidiary freight tracks shall be as follows: Beginning at a point in the centerline of track 211/4 feet above the top of rail; thence horizontally 4 feet 2 inches; thence downward at an angle to a point 15 feet above the top of rail and 8 feet laterally distant from the centerline of track; thence downward to a point 4 feet above the top of rail and 8 feet laterally distant from the centerline of track; thence downward on an angle to a point level with the base of rail and 5 feet laterally distant from the centerline of track.

b) Railroad Bridges Spanning Main Tracks or Subsidiary Freight Tracks. The clearances of all railroad bridges spanning main tracks or subsidiary freight tracks shall be as follows: Beginning at a point in the centerline of track 211/2 feet above the top of rail the vertical clearance line shall extend thence horizontally each way to points 8 feet from the centerline of track, from which points the horizontal clearance lines shall extend vertically downward to points level with the base of rail.

c) Highway Bridges Spanning Railroad Tracks. A vertical clearance of not less than 23 feet above the top of rail shall be provided for all new and reconstructed highway bridges constructed over a railroad track. Beginning at a point in the centerline of track 23 feet above the top of rail the vertical clearance line shall extend thence horizontally each way to points 9 feet from the centerline of track, from which points the horizontal clearance lines shall extend vertically downward to points level with the base of rail. For purposes of this subsection, reconstruction includes pier and/or pier cap replacement, girder removal and/or replacement, and/or widening of existing piers, pier caps or decks. All other work shall be considered as rehabilitation, in which case the existing clearance or a minimum of 211/2 feet vertical clearance (whichever is greater) must be attained.

d) The Commission may, by order, permit a lesser clearance if it determines that the 23 foot clearance standard cannot be justified based on engineering, operational, and economic conditions. A recommendation for a lesser clearance may be submitted to the Commission, followed by an evidentiary hearing of all the parties involved before an Administrative Law Judge.