In Illinois, Chick-fil-A and Wendy's had the slowest fast food drive-thru times at 325 seconds and 275 seconds, respectively.

CBS News ranked fast food drive-thru efficiency in Illinois, with Chick-fil-A reported to have the slowest drive-thru time of 10 popular restaurants at 325 seconds (about 5.5 minutes) on average. Wendy's, credited with pioneering the drive-thru concept, was also among the slowest with 275 seconds (nearly 5 minutes). The ranking is based on average wait times.