92 Ill. Adm. Code 544.30
Traffic Signals
Section 544
Section 544.30 Traffic
Signals
a) Signals may be installed only where conditions meet the
warrants established in the current State of Illinois Manual on Uniform Traffic
Control Devices for Streets and Highways to be codified as 92 Ill. Adm. Code
546 or supplemental Department policy.
b) The Department may regulate signal sequences and control
timing of all signals on State highways when it deems it necessary to do so.