I've been eating a lot of fast food this summer because of my weekly trips to Lexington.
Spending a significant amount of time in the drive-thrus at various restaurants has led me to determine the most important rule of drive-thrus:
You have to scoot up when the car in front of you scoots up.
There is a delicate system at work in a drive-thru. You order, you should be ready to pay when you get to the payment window, and then your food is usually ready by the time you get to the second window. It's very quick, but it depends on everyone moving smoothly.
When someone is looking down at their phone, fiddling with the radio or turned around talking to their children and therefore misses the fact that all the cars in front of them have moved, this throws the balance off.
This is especially bad when the person is positioned in such a way that the next person can't order, because the distracted driver is now able to cruise through both stops since all the cars in front of them are gone.
Then, the person who hadn't been able to order efficiently has to sit and wait for their food at the window, in addition to the fact that they had to wait longer to order in the first place.
That is an extreme example, though, and only happened where I was twice over the course of the summer. If I had been the car behind the distracted driver in that case, I would have honked, but unfortunately it was happening one person in front of me both times.
A much more common occurrence is where there is a significant amount of space between the car in front of me and the car in front of them. I am about a foot away from being able to reach the ordering station, and if the car would just scoot up even a little bit, I would be able to order.
This is a frustrating position because I feel rude honking, but you really are hindering my ability to order, so like, please move! I think in this situation, it depends on how much space there is open. During one such occurrence, I ended up honking because there was about a full car length open in front of the car in front of me.
So anyway, I think the thing that bothers me the most about people making a drive-thru slower is that the whole point of a drive-thru is to make things quicker.
So the moral of the story is: If you're not going to pay attention and keep up, go inside.