In many places in the U.S. the demand for telephone exchanges is very
> high for a variety reasons. This has result in area code splits and
> overlays. NJ started off with one area code and now has nine.
> But some states still only have one area code. I understand some
> states are not growing very fast in population, indeed, some rural
> towns are losing population. This includes: Alaska, Idaho, Montanna,
> North Dakota, South Dakota, and Wyoming. (Not counting some other
> single-code states).
> Given the rural/low growth aspect of places in some of these states, I
> was wondering if telephone service may still have some old fashioned
> features to it. For example, would such areas have:
> 1) Traditional party line service, since it's not worth the cost to
> upgrade lines out to people's farms?
In almost all places single party lines have been cheaper for the telco for decades. Where they have been forced to continue to offer party line service, they have used bridges at the CO, not in the field. The forcing comes when they go to the PUC and tell them party lines cost more, and the PUC replies go to all single party lines at the party line rate. I think they have mostly managed to buy off the PUCs.
2) Five digit dialing in some areas not well populated or served by
> community dial offices?
Five digit dialing was a feature of old panel switches which could be set up to throw out the first two digits if the local exchange was being dialed, and use them otherwise. My old hometown had one of those for a long time.
I believe everything is ESS nowadays, but that pays for itself by
> eliminating the need for technicians to visit remote unattended
> switches. Probably some community dial offices have been converted to
> concentrators or feeders to a larger CO elsewhere.
There are certainly CDOs still around in the boondocks. Many of those old brick windowless boxes have a pad out back with a fiberglass hut mounted on it. Likely that contains a DMS-10 or DCO. Those are small ESS systems that can serve several thousand lines.