Most people say it's worth the wait...but if you really don't want to be stuck in a long fast food drive-thru line then you need to know that according to a new study....Chick-fil-A has the slowest drive-thru in America. You will spend an average of 8minutes and 29 seconds getting your food at Chick-Fil-A. The reason might be because more people go to the restaurant which causes a longer wait. Among the top ten fast food locations, KFC had the quickest drive-thru wait. The list of restaurants in the study includes Chick-fil-A, Wendy's, Burger King, Dunkin', McDonald's, Arby's, Carl's Jr., Hardee's, Taco Bell, and KFC.