This is just a guess: at the end of each partitioned lane there’s two red lights. On the far right side, you can see a little green light on one of them, with cars exiting from that side. I’m guessing they’re controlling when each lane gets to merge into the final booths, so it’s not as much of a free-for-all.
Thank you for posting here. I was looking for this. I installed it once before using the Reddit directions, but I need to reinstall an updated version and had lost that post.
Or something cheeky and adjacent would be fun too. Like “Once I pop, your buns are hot.”