The Illinois Department of Transportation has the responsibility to construct and maintain mailbox turnouts at approved locations on State Highways to provide all-weather surfaces and allow the mail carrier's vehicles to clear all or part of the traveled roadway when stopped to service the mailbox.
On new, or reconstructed, State highways, the construction of mailbox turnouts shall be an integral part of the design and construction and shall be built in accord with Highway Standard 2171 (Illustration 1) of the Design Manual. When the project design provides adequately stabilized shoulders, of adequate width, no additional mailbox turnouts will be constructed.
Ill. Admin. Code tit. 92, § 532.210