Trains are super effective for rural areas. I'm more than happy to drive my beat up pickup, tractor, bike, walk or ride a horse down a rural road to the train station. Doing the same on the highway is stressful, as none of those mode of transports are safe at highway speeds. Modern roadways are an artificial monopoly that poor people can't participate in.

Only 20% of America lives in a rural area, so odds are it’s irrelevant to most struggling people.

The census definition of "urban" is kind of absurd. If I'm reading it right, living in a town of 2500 is "urban." If I'm reading it wrong, living in a town of 50,000 is "urban." Either way, you'd likely consider a lot of that 80% rural.

Where is that definition from?

The 2020 census proposes using "385 housing units per square mile as the primary criterion for determining whether a census block qualifies for inclusion in an urban area". Previously it was 1000 people per square mile (or equivalent to the above with 2.6 persons per household).

https://www.federalregister.gov/documents/2021/02/19/2021-03...

Note that's only in the "proposed changes section, and that there is still much more information in that document. That change seems to determining how much of a town is an urban tile, but is not the primary designation of urban.

I guess density is the real measure.

While I haven't seen it work very well, it's not the case that it's impossible. My mother has been the superintendent at a number of places in the rural southwest. They manage to get the kids to school via bus.

So it isn't the case that rural public transportation simply can't work.