You can definitely tell which states enforce speed laws around where I live (in a tri-to-quad state area). You cross the state line for one state, and all of a sudden all the trucks are doing the speed limit. Cross back, and you'd think you were at a Nascar race. The cars seem a little denser on that issue, lol!

From a safety perspective, I get the idea of trucks needing a slower speed limit for mechanical reasons, but from a practical standpoint, it's absolute craziness. Every couple minutes, you end up having to pass a truck or 2 or 10. Then in my state, trucks aren't supposed to use the far left lane at all. HAH! They buddy up with another truck and totally block the highway. I've never seen one pulled over for that - speeding yes, obstructing progress, never!