"Kilometer" is another popular unit, which is never called "kilo", lately I heard it's informally called "click" in US. Logic is the same, kilometer means a thousand meters, and meter is the base unit of length.
I once worked with someone from Egypt who used "kilo" for kilometers. He's the only person I've met who did that. I've no idea if that was just a personal quirk or if that was a common shortening elsewhere in the world.