The numbers on U.S. interstate highway signs may seem random, but they can actually be an important navigation tool. This short video shows how it all works. For starters, the interstate system is ...

Ever wondered how the highway and interstate numbers came to be? What do they even mean if they mean anything at all? Behind those numbered shields displayed on the signs is a mathematical logic grid ...

It’s my understanding that north and south interstate routes are odd numbered and the ones running east and west are even numbers. Why is Interstate 26, which runs north and south, an even number? Why ...

Q: It’s commonly understood that east-west interstate highways are given even numbers (Interstate 80, for example) and north-south routes get odd numbers (I-81). Is it also true that there are other, ...