Reuters

McDonald's is planning to add a third window to its drive-thru lanes in response to mounting customer complaints about slow service, Bloomberg's Leslie Patton reports .

The change comes as wait times at McDonald's drive-thrus are estimated to be the longest in at least 15 years, according to a recent study by QSR Magazine .

Currently, McDonald's restaurants have one window where drive-thru customers pay for their food and another where they pick up their purchases. The restaurant is adding a second food pickup window.

The fast food giant will begin restructuring the drive-thrus next year.

"It enables customers to pull forward to receive orders at a third window when their order is not yet ready," McDonald's spokeswoman Lisa McComb told Bloomberg, adding. that it "will enable us to better serve more customers quickly."

Analysts say drive-thru waits have been getting longer because new menu offerings like Pumpkin Spice Lattes and Chocolate Chip Frappes are distracting employees from the brand's core product.

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