Your Only Job At The Drive-Thru Is To Know What You Want
You pull your car up to the little speaker box at a restaurant drive-thru. You greet the person on the other end with a courtesy hello, and then say what you want. Then, while remaining in your car, you drive up to either the first or second window and hand over your choice of payment. The person on the other side of the window hands your food. You drive off, and the car behind you takes your place.
This is the ideal customer-worker experience when you're in a drive-thru lane. It is so simple that it would be impossible to imagine doing it any other way or see how anyone could possibly mess up such a basic procedure. But you would be surprised how many things can happen, whether accidental or purposeful, that annoy fast-food workers who find themselves manning the drive-thru. It could be something like a person holding up the line by ordering large quantities of food or people driving off without paying or picking up the order (according to some fast-food workers on Reddit). If the stories of fast-food workers are to be believed, you'd be surprised to learn how many people seem unable to grasp how the drive-thru works.
But there's one common annoyance that would no doubt upset any fast-food worker, whether at a McDonald's, In-N-Out, or even one of two of the nation's historical drive-thrus: not knowing what you want before you pull up to the speaker.
Don't hog the drive-thru lane to figure out what you want
"Welcome to McDonald's. What can I get for you?"
"Hi, I'll have uh ... a Big Mac, I guess? Actually, I'll take a McCrispy, and medium ... no, wait, large fries, and maybe a ... hmmm, an order of McNuggets. Or maybe ..."
You've probably heard this conversation as an employee or passenger waiting in the car behind the speaker. Even if you're not at a McDonald's, any fast-food drive-thru has that customer who can't seem to figure out what they want when they pull up to the speaker. This not only takes up the time of you and the employee but everyone else waiting in line too. A drive-thru is meant for quickly ordering food and leaving, not for someone to sit around and take their sweet time in.
Perhaps this person isn't doing it to be purposefully rude. The person may just be taking their time because they don't want to sound like they're barking orders at the employee on the other side. Pulling up to the speaker and screaming your orders without even a hello would be wrong, right? But even if this is done of supposed courtesy, it still doesn't change the fact that taking your time to order means you're holding up the line.
Ultimately, deciding what you want to order before pulling into the drive-thru is best.
Make sure everyone else in the car knows what they want too
Let's put ourselves in the position of the employee stationed at the drive-thru. While a car full of people pulls up to the speaker, and each person is trying to figure out what they want (perhaps making you repeatedly change the order while they mull over what they want), there is a line of cars with other customers who are growing very impatient. Impatient customers usually mean angry customers, and if the current car doesn't hurry up and figure out what they want, you're going to get an earful from a few of these hungry and exhausted customers.
The bottom line is before you get your family or friends in the car and head to a fast-food restaurant, ensure everyone is on the same page about what they want to eat. This saves time not just for you but also for the employee and the other patrons who frequent the drive-thru.