cos

I was curious so I looked up the data and apparently 70 does exist as close to you as NH and PA, but presumably not places you've needed to go. 75 in Maine. But yeah, pretty much all the rest of the 75 is in Great Plains and Rockies states, plus 80 in Utah and 85 in Texas. I was surprised Alaska maxes at 65, though I bet it's not much enforced. Lowest is Hawaii at 60, but then, there's not very far to go there.