At least on the west coast of the US, Interstates allow the fastest speeds and they extend through multiple states. Between cities the speed limits are higher, but the speeds are reduced as they go through cities. There are rarely any stop signs or traffic lights on a freeway interstate.
Highways will often have a speed limit around 55-65 MPH and they might have stop signs or traffic lights.
I notice California allows much faster driving on city streets than Oregon or Washington. California might allow 45 MPH in an area that would be 30-35 MPH up here.
Until 1999, Montana had no official speed limit. One could be ticketed for driving beyond what was reasonable, as determined by the highway patrol. Until 2005 one could drink and drive in Montana, so long as they weren't "impaired" or legally intoxicated. I always wondered why it was permissible to have a couple beers at a pub and take them along in your belly while you drive, but you couldn't put those beers in your belly as you drove.
