Chick-fil-A's slow drive-thru time doesn't mean the chicken sandwich chain, which is closed on Sundays, is completely slow or bad at business. A caveat to the study is that much of the wait time is based on popularity. Chick-fil-A restaurants average 4.74 cars in its drive-thru, which is much higher than the average of 2.76 cars among the 10 chains in the study. When looking at the other fast food competitors, KFC had the quickest drive-thru time but only an average of two cars – nearly three fewer than Chick-fil-A. Visit the link in our bio for more of the average drive-thru wait times.