92 Ill. Adm. Code 1500.160
Bridges
Section 1500
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 21¼ 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 21½ 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 21½ 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.