It varies widely from State to State, and it is never more evident as when you cross a State border on one of the Interstate highways. The sudden change in road quality can be dramatic. There is also little correlation between road quality and the amount of money spent per kilometer on literally the same stretch of border-crossing highway -- the poor quality side of the border may be spending several times what is being spent on the good quality. Some States have very nice highways that are built and maintained at modest cost.

The high variance in road quality and cost is a very visible example of how varied the effectiveness and efficiency of individual State governments can be in the US.

It is indeed very different from state to state, depending on the state's tax base and priorities, and also within states from locale to locale, at times.

It all depends how many rich people live in the city. You can tell when you cross city/town borders because the roads become noticeably better or worse.

I think the road systems are pretty badly designed pretty much everywhere.

Cross walks that cross 3 lanes (each side)with traffic going 40mph and no signal.

Stop signs that doesn't tell you if the intersecting direction stops or not.

Half-assed painted gutters for bike lanes.

Places with 4 signs to indicate when you can park, each with different (sometimes overlapping) times and conditions.

the list goes on.