In the US, it’s called a line. In Canada, it’s often referred to as a line-up. Pretty much everywhere else, it’s known as a queue. My friend Benjamen Walker is obsessed with queues. He keeps sending me YouTube clips of queue violence. This preoccupation led him to find a man known as “Dr. Queue.” Richard Larson is a queue theorist at MIT and he talks us through some of the logic behind the design of queues. Whereas US companies like Wendy’s and American Airlines once prided themselves on their invention of the single, serpentine, first-come first-served queue, more and more companies are instituting priority queues, offering different wait times for different classes of customers.