New Research Reveals Fastest and Slowest Drive-Thru Chains in the U.S. When you’re craving fast food, the last thing you want is to spend ages in the drive-thru line. A recent study by QSR Magazine has shed light on which fast-food chains have the speediest and slowest drive-thru services, as well as the accuracy of orders and the friendliness of staff. To conduct the study, QSR Magazine made 1,491 drive-thru visits in June and July,...