[Tervuren]

This will likely vary.

I have observed at Chic-Fil-A the car that entered the drive through line as I get out.

I pretty much have my food before the car.

it will vary first based on popularity of the option and the store's ability to meet that option.

At peak times drive throughs have additional order takes for cars to help with the load. If you hit a heavy load without additional personnel on the option you take that can be longer. I generally avoid going out at peak times.

The second thing is food preparation, you can't give out orders faster than food can be made. What some one orders can hold things up. In the drive through it holds up EVERYONE if something has run out for one customer after ordering.

Where as in the check out line inside that one person just waits longer.

I fundamentally prefer to park and walk in, I have more enjoyment that way.