While you're underway there aren't many other things you should be keeping an eye on, but that was an absolutist stance to make a point. I know people are going to be glancing at fuel or temperature or whatever.

> I would've said that the speedometer really isn't needed - if you go with traffic and don't hang out in the passing lane, you're never going to get in trouble

That's really location specific, and situation specific. We can't go over ~5kmph faster than the limit here without getting fined by speed cameras. Also 10kmph faster on a highway versus 10kmph faster in town are very different. 10kmph faster in town could be the difference between killing someone or not hitting them at all.

I do somewhat agree though, I think "driving to the conditions" for me personally would be totally fine, I'd probably trend to driving slower than the speed limit. But if you had no limit and no enforcement, people would be abusing it all the time. Someone in a hurry in town would easily cause trouble. The tradeoff for limiting that is having to check your speedometer.

10kmph = 6.2mph.