Similar to the recent news item "why does nobody live in 90% of New Zealand" .. in the wealthy and wonderful US of A, there are vast areas where there are no general practitioner doctors on call, and some areas where there are no hospitals at all.
As mentioned in other comments, the road network is less than half of the accessibility story, the rest is about money.
> in the wealthy and wonderful US of A, there are vast areas where there are no general practitioner doctors on call,
If by that you mean doctors who make home visits then I have news for you: there are entire western countries where doctors do not make house calls. In Norway you are expected to to make an appointment to visit your GP, or make your own way to an outpatient clinic (legevakt) or the accident and emergency department at a hospital. If you can't do any of that you are expected to call an ambulance.
I haven't heard of GPs making home visits in the UK either in recent and not so recent decades.
great greetings to Norway ! .. no, I don't mean "house call" .. that disappeared here more than fifty years ago. I mean that in an entire area, there is not one single doctor in any way.
Similar to the recent news item "why does nobody live in 90% of New Zealand" .. in the wealthy and wonderful US of A, there are vast areas where there are no general practitioner doctors on call, and some areas where there are no hospitals at all.
As mentioned in other comments, the road network is less than half of the accessibility story, the rest is about money.