(A) Whenever any person driving a vehicle approaches a railroad grade crossing, where the driver is not always required to stop, the person must exercise due care and caution as the existence of a railroad track across a highway is a warning of danger, and under any of the circumstances stated in this section, the driver shall stop within 50 feet but not less than 15 feet from the nearest rail of the railroad, and shall not proceed until the tracks are clear and he or she can do so safely. The foregoing requirements shall apply when:
(1) A clearly visible electric or mechanical signal device gives warning of the immediate approach of a railroad train or railroad track equipment;
(2) A crossing gate is lowered or a human flagman gives or continues to give a signal of the approach or passage of a railroad train or railroad track equipment;
(3) A railroad train or railroad track equipment approaching a highway crossing emits a warning signal and the train or railroad track equipment, by reason of its speed or nearness to the crossing, is an immediate hazard;
(4) An approaching railroad train or railroad track equipment is plainly visible and is in hazardous proximity to the crossing;
(5) A railroad train or railroad track equipment is approaching so closely that an immediate hazard is created. Whenever a person driving a vehicle approaches a railroad grade crossing where the driver is not always required to stop but must slow down, the person must exercise due care and caution as the existence of a railroad track across a highway is a warning of danger, and under any of the circumstances stated in this section, the driver shall slow down within 50 feet but not less that 15 feet from the nearest rail of the railroad and shall not proceed until he or she checks that the tracks are clear of an approaching train or railroad track equipment.
(B) No person shall drive any vehicle through, around, or under any crossing gate or barrier at a railroad crossing while the gate or barrier is closed or is being opened or closed.
(C) Local authorities are authorized to designate dangerous highway grade crossings of railroads and to erect stop signs thereat. When stop signs are erected at railroad grade crossings, the driver of any vehicle shall stop within 50 feet but not less than 15 feet from the nearest rail of the railroad, and shall proceed only upon exercising due care.
(D) No person shall, while driving a commercial motor vehicle, fail to negotiate a railroad-highway grade railroad crossing because of insufficient undercarriage clearance.
(ILCS Ch. 625, Act 5, § 11-1201(a), (b), (c), (d-1)) Penalty, see § 70.99