625 ILCS 5/11-901: Vehicles approaching or entering intersection.

(a) When 2 vehicles approach or enter an intersection from different roadways at approximately the same time, the driver of the vehicle on the left must yield the right-of-way to the vehicle on the right.

(b) The right-of-way rule declared in paragraph (a) of this Section is modified at through highways and otherwise as stated in this Chapter.