Or pull a Chick-fil-a and send someone out with a tablet to take all orders and possibly payments. Takes one extra person (or no extra people if you have a McDonald’s style pay window and food window), and the line moves faster because nearly all orders are ready as soon as the driver reaches the window, or shortly after. No need to raise prices (and thus risk losing customers) if you can increase the throughput with minimal cost.

One of the biggest issues with drive thru lines is that often very few people have actually placed their order at a time, so the kitchen isn’t actually running at the pace needed to handle all the orders that are about to come in. Get the orders earlier and increase the pace in the kitchen, everything else can keep up because the kitchen is the bottleneck in a place like that.