What’s Up With That: Why You Always Seem to Choose the Slowest Line

You run into the grocery store to quickly pick up one ingredient. You grab what you need and head to the front of the store. After quickly sizing up the check-out lines, you choose the one that looks fastest.

You chose wrong. People you could swear got in other lines long after you chose yours are already checked out and headed to the parking lot. Why does this seem to always happen to you? What kind of a cruel universe would allow such a thing to happen? It’s not fair!

Well, as it turns out, it’s just math that is working against you.

When you’re selecting among several lines at the grocery store, the odds are not in your favor. Chances are, the other line really is faster. Mathematicians who study the behavior of lines are called queueing theorists, and they’ve got the numbers to prove this. Their models also underlie a diverse set of modern problems, including traffic engineering, factory design, and internet infrastructure. At the same time, queueing theory provides a fairer way to checkout at the store. The only problem is that many customers don’t like it.

http://www.wired.com/2014/07/whats-up-with-the-other-line-is-always-faster/