Drive-thru cars per hour: how to work out your lane's throughput

Divide 3,600 by the seconds each car ties up your slowest station, usually the speaker or the pickup window. The answer is the most cars your lane can serve in an hour. If each car ties up the pickup window for 63 seconds, the lane tops out near 57 cars an hour, however quick the speaker is.

This guide covers the arithmetic: which station sets your limit, what a second order point adds, and how to check the numbers at your own lane. Our drive-thru timer guide shows how to time cars by hand, and our guide to speeding up a drive-thru lists fixes for each stage.

What sets a drive-thru's cars per hour?

A lane is a row of stations: the order point, then one or two windows, with the kitchen behind them. Each station serves one car at a time. The time a station is tied up per car is the time the car spends there plus the few seconds the next car takes to pull in. Call that the station time.

The station with the longest station time sets the pace for the whole lane. Cars queue in front of it, and the stations after it wait between cars. Total time, from joining the line to getting food, is each guest's wait. It grows as the queue in front of the slowest station grows.

Station	What ties it up	How to time it at the peak
Order point	Greeting, the order, repeats, the readback and the total	From one car stopping at the speaker to the next car stopping there
Pay window, if separate	Card or cash, change, loyalty scans	From one car stopping at the window to the next
Pickup window	Waiting for food, checking the bag, handing it out	From one car stopping at the window to the next
Kitchen	Making and bagging each order	Orders finished in each 15-minute block

How do you work out cars per hour?

For each station, cars per hour equals 3,600 divided by its station time in seconds. If you run two of the same station side by side, double the result. The lowest figure is your lane's limit.

Here is a made-up single lane at lunch, with separate pay and pickup windows. Each station time adds 8 seconds for the next car to pull in.

Station	Seconds with the car	Plus pull-in	Station time	Cars per hour
Order point	70	8	78 seconds	46.2
Pay window	30	8	38 seconds	94.7
Pickup window	55	8	63 seconds	57.1

The order point limits this lane to about 46 cars an hour. Take 10 seconds off each order, with a shorter greeting and fewer repeats, and its station time drops to 68 seconds, a limit of 52.9 cars. Take off another 10 and the order point could handle 62.1 cars, more than the pickup window's 57.1. From then on the pickup window sets the pace, and a faster speaker adds no more cars until the window speeds up too.

Check the kitchen as well. At 57 cars an hour, the make line has to finish an order about every 63 seconds, or about 14 orders in each 15-minute block. If it falls behind, cars wait at the pickup window and that station time grows.

What does a second order point add?

In a Y-lane, two speakers feed one set of windows. In the example, two order points at 78 seconds could take 92.3 orders an hour between them. The pay window can handle 94.7 cars and the pickup window 57.1, so the lane now tops out at about 57 cars an hour, up from 46. That is about 11 more cars an hour from a second speaker.

To get more from a Y-lane, shorten the pickup window's station time: pull large orders forward to a waiting space, pour drinks as soon as the order is placed, or add a second pickup point. Two complete lanes, each with its own windows, can double the limit if the kitchen keeps up. Our dual-lane guide covers the layouts and how to match orders to cars after the merge.

Layout	How to find the limit
Single lane, one window	3,600 divided by the longer of the order point and window station times
Single lane, pay and pickup windows	3,600 divided by the longest of the three station times
Y-lane: two order points, one set of windows	The lowest of twice the order point figure, the pay window figure and the pickup window figure
Two complete lanes	Each lane's own limit, added together, then checked against the kitchen
Order-ahead lane	App orders skip the speaker, so count them only at the windows they share

Where does the time go in the 2025 study?

The 2025 QSR Drive-Thru Report, run with Intouch Insight, timed 165 mystery-shop visits at each of 13 chains in June and July 2025. It splits each visit in two.

Measure	The report's definition	Average
Wait time	Entering the line to reaching the speaker and starting the order	80.8 seconds
Service time	Starting the order to receiving the food	254.6 seconds
Total time	Entering the line to receiving the whole order	335.4 seconds

Service time makes up about three quarters of the total, 254.6 of 335.4 seconds. It covers the order point, the drive to the window and the window itself. The public write-up does not give that split.

These are times for one guest, and they say little about capacity. Intouch's October 2025 notes on the study put the average number of cars in line at 1.20 in 2025, slightly below 1.23 the year before and down from more than two per lane at the 2020 peak. With about one car ahead, most visits did not push the lane to its limit. Neither write-up gives a cars-per-hour figure, so use your own count.

How many cars will be in the lane at once?

Multiply cars per hour by each car's total time in hours. At 46 cars an hour and 335.4 seconds a car, the lane holds 46 times 335.4 divided by 3,600, or about 4.3 cars on average, including the cars at the speaker and the windows. Compare that with the number of cars your lane holds before the line reaches the street. Cars arrive in bunches at the peak, so plan for well above the average.

How do you measure your own lane?

1. Pick your busiest hour, when a car is waiting behind the speaker for most of it. Station times show the limit only when the next car is ready to pull in.
2. Count the cars leaving the pickup window in each 15-minute block, and multiply by four.
3. For 20 cars, write down the clock time each car stops at the speaker and at each window. The gap between one car and the next at the same station is that station's time. The worksheet in the timer guide works for this.
4. Work out each station's limit with the tables above.
5. Compare your count with the lowest limit. If they are close and cars are queuing, that station is your constraint. If your count sits well below every limit, the lane had room to spare that hour.

Station	Average seconds between cars (20 cars)	Stations side by side	Cars per hour limit
Order point
Pay window
Pickup window
Kitchen (orders finished per 15 minutes, times four)

What if an AI order-taker is at the speaker?

The same arithmetic applies. An AI order-taker changes the order point's station time, and the windows stay as they were. In the 2025 report, service time at lanes with AI voice ordering averaged 232.8 seconds, against 254.6 seconds for the other lanes, across 120 orders at three chains. If the pickup window is already your limit, a faster order point will not raise your count.

Maple's drive-thru unit, in early access with a small number of restaurants, stands beside the existing speaker post and shows the guest a live cart. For any trial, time the order point and count cars per hour before and during it. The pilot checklist lists what else to record.

Published by Maple, which sells phone ordering and an early-access drive-thru unit. This AI-assisted guide combines the 2025 QSR Drive-Thru Report and Intouch Insight's study notes with original throughput arithmetic and a worksheet. The worked example is made up. It does not report a Maple timing study or promise any gain in cars per hour.