Earlier quoted context omitted.
Do you have a source for that? I had always understood the speed limit as simply being an objective, statutory codification of the subjective notion of "appropriate maximum speed for conditions" Which fits well with dynamic speed limits cropping up in places that get regular bad weather
I started to reply to thinking there was a federal minimum speed limit but decided I should confirm what I believed and glad I did because I was wrong. In the US, states have full control over the speed limits that are set on both the state hwys and the interstate freeways within that state. That said, I'm pretty sure every freeway I've ever been on had a posted minimum 45mph speed limit, and bikes are not allowed. W…
There are exceptions, especially in the US West, where interstates may be the only path for miles and miles through some mountain ranges. Of course, they mostly have wide shoulders where people ride.