Why Do Area Codes Seem So Random?

The Interstate Highway system seems to have a logic to it, with even numbers running east-west and odd numbers running north-south. And the highway numbers get higher the farther east you go, or the farther north you go. Zip codes also have an obvious pattern of starting small in the east and getting larger as you head west.

But what is it about area codes? They seem totally random when you look at a map of them across the country. But you can pick out a pattern if you know what you're looking for. This video explains it.