(A) School speed zones.
(1) For the purpose of this section, SCHOOL means the following entities:
(a) A public or private primary or secondary school;
(b) A primary or secondary school operated by a religious institution; or
(c) A public, private or religious nursery school.
(2) On a school day when school children are present and so close thereto that a potential hazard exists because of the close proximity of the motorized traffic, no person shall drive a motor vehicle at a speed in excess of 20 mph while passing a school zone, or while traveling on a local, county or, state roadway on public school property or upon any public thoroughfare where children pass going to and from school.
(3) For the purpose of section, a SCHOOL DAY begins at 6:30 a.m. and concludes at 4:00 p.m.
(4) This section shall not be applicable unless appropriate signs are posted upon streets and highways under their respective jurisdiction and maintained by the village wherein the school zone is located. With regard to the special speed limit while passing schools, such signs shall give proper due warning that a school zone is being approached, and shall indicate the school zone and the maximum speed limit in effect during school days when school children are present.
(625 ILCS 5/11-605(a))
(5) Nothing in this chapter shall prohibit the use of electronic speed-detecting devices within 500 feet of signs within a special school speed zone indicating the zone, as defined in this section, nor shall evidence obtained thereby be inadmissible in any prosecution for speeding; provided, the use of the device shall apply only to the enforcement of the speed limit in the special school speed zone.
(625 ILCS 5/11-605(c))
(B) Highway construction or maintenance speed zones.
(1) (a) A person may not operate a motor vehicle in a construction or maintenance speed zone at a speed in excess of the posted speed limit when workers are present.
(b) A person may not operate a motor vehicle in a construction or maintenance speed zone at a speed in excess of the posted speed limit when workers are not present.
(2) Nothing in this chapter prohibits the use of electronic speed-detecting devices within 500 feet of signs within a construction or maintenance speed zone indicating the zone, as defined in this section, nor shall evidence obtained by use of those devices be inadmissible in any prosecution for speeding; provided, the use of the device shall apply only to the enforcement of the speed limit in the construction or maintenance speed zone.
(3) (a) As used in this section, a CONSTRUCTION OR MAINTENANCE SPEED ZONE is an area in which the Department, Toll Highway Authority, or local agency has posted signage advising drivers that a construction or maintenance speed zone is being approached, or in which the Department, Authority, or local agency has posted a lower speed limit with a highway construction or maintenance speed zone special speed limit sign after determining that the preexisting established speed limit through a highway construction or maintenance project is greater than is reasonable or safe with respect to the conditions expected to exist in the construction or maintenance speed zone.
(b) If it is determined that the preexisting established speed limit is safe with respect to the conditions expected to exist in the construction or maintenance speed zone, additional speed limit signs which conform to the requirements of this division (B)(3) shall be posted.
(c) Highway construction or maintenance speed zone special speed limit signs shall be of a design approved by the Department. The signs must give proper due warning that a construction or maintenance speed zone is being approached and must indicate the maximum speed limit in effect. The signs also must state the amount of the minimum fine for a violation.
(625 ILCS 5/11-605.1(a) - (c))
(4) The Department of State Police and the village Police Department have concurrent jurisdiction over any violation of this division (B) that occurs on an interstate highway.
(625 ILCS 5/11-605.1(e-5))
(5) For a second or subsequent violation of this division (B) within two years of the date of the previous violation, the Secretary of State shall suspend the driver’s license of the violator for a period of 90 days. This suspension shall only be imposed if the current violation of this division (B) and at least one prior violation of this division (B) occurred during a period when workers were present in the construction or maintenance zone.
(625 ILCS 5/11-605.1(g))
Penalty, see § 71.999