Ill. Admin. Code tit. 92, § 530.430
a) General
b) Fully Access-controlled Highways
1) Longitudinal Water Mains
New longitudinal water mains will not be permitted between the access-control lines of fully access-controlled highways. Existing longitudinal installations shall be relocated if they cannot be serviced except from through-travel lanes, shoulders, or ramps of the highway. Longitudinal water mains may be permitted outside the access-control lines of fully access-controlled highways if frontage roads or other corridors provide access for servicing the lines.
2) Water Main Crossings
Water main crossings of fully access-controlled highways may be permitted under the following conditions.
c) Conventional Highways
1) Longitudinal Water Mains
Longitudinal water mains may be permitted on the right-of-way of conventional highways if they conform to the general provisions of this Section.
2) Water Main and Service Crossings
Water main and service crossings of conventional State highways may be permitted under the following conditions: