92 Ill. Adm. Code 554.508
Overheight
Section 554
Section 554.508 Overheight
a) The maximum overheight for which a permit may be issued is
governed by overhead clearances provided to the Permit Office by each District.
The height of the move should be measured from the uppermost point of the
object, after it is loaded, to the ground. The practical maximum height is 15
feet.
b) The maximum height authorized on Chicago area controlled
access highways is 13 feet 6 inches.
c) On all highways, a 3-inch clearance generally is specified to
allow for bounce. Overheight movements that are extremely long may require
additional clearance at underpasses where the approach pavement dips abruptly
at the structure.
d) The Permit Office does not check the vertical clearance of a
route when the applicant indicates the height of the vehicle and load is
"legal". If the applicant indicates the height is 13 feet 6 inches,
which is the legal height, no additional clearance is provided when the
vertical clearance of the route is checked.
e) For movements at 16 feet or greater in height, the applicant
shall perform a route survey, listing all overhead obstructions, to ensure the
clearances will enable the object to pass under without difficulty. The
surveyed route must clear all structures by three inches. The measurements of
all structures are listed by the Department at http://www.dot.il.gov/tpublic.html#truckers
or on the online truck permit routes or map at www.gettingaroundillinois.com.
In addition, all routes must be clear of any legal weight structures, ton
structures and temporary and permanent restrictions that may apply to the load.
f) For movements at 17 feet in height, or greater, it is the
responsibility of the applicant to contact all companies with overhead utility
facilities and to indicate on the application the company, name of person contacted
and telephone number. A District investigation, consisting of a route survey
by District personnel, will be required.