[samtheman]

I do it anyway out of courtesy to the trooper. Same for joggers/walkers/bikers on the local roads.

Same here. I've always done this, reflexively, without thinking. Just always seemed like a good idea.

But it's good to know that it's not just a good idea, it's the law.

(Which reminds me of a T-shirt I saw once:

186,000 miles per second. It's not just a good idea. It's the Law.)

[DariusBane]

But it’s good to know that it’s not just a good idea, it’s the law.

Why do you need a law? I think we have plenty of laws. We don’t need any more.