Fast food drive-thru times are slowing down.

According to an annual study by QSR magazine, the average drive-thru wait time is nearly 181 seconds. That's about eight seconds slower compared to last year's average, which was nearly 173 seconds.

The study measured the average drive-thru speed, from order to pick-up, at seven major fast food restaurants, including Burger King, Chick-fil-A, Krystal, McDonald’s, Taco Bell, Wendy’s and Taco John’s.

Chick-fil-A had the slowest time with 204 seconds.  Wendy's was the fastest with an average drive-thru wait time of nearly 134 seconds.

Researchers say the overall slowdown is mostly the result of busier drive-thru lanes and more complex new products being offered at fast food chains.

Click here to read the complete study.