I like trains and I'm in favor of them, but the majority of the US isn't suited to them. The future may change that, and I hope it does, but if we want something that can make an impact right now smaller cars nationwide are the best "good" but non-perfect answer.

Every area is different, so I'll just go with what's local to me right now.

Where I currently live (rural rust belt Midwest) the logical right of ways for railroads already exist and they run between cities and significant towns.

The problem is that these right of ways - which used to be railroad right of ways - are all bike paths now. In one respect, it wouldn't be too much trouble to convert them back to rail. We wouldn't need to break up neighborhoods or demolish much infrastructure. Just lay rail and add crossings and stations.

On the other hand it would also destroy one of the few things that makes life bearable around here. It's free public space and it's used by walkers, joggers, skaters, and cyclists. I live within view of one. Every day and in all weather, I see an incredible variety of people pass by. Elderly, young families, people on horseback, those road cycle-bros, cycles with camping gear, mothers pulling kids in wagons. Sometimes emergency services use it to bypass a slower dirt road when they're needed at a remote community nearby.

They're safe and well maintained. They're like linear parks that also offer a safe non-motorized transport option between towns.

Back when I was on Reddit I lurked on the local city sub. Whenever a potential migrant would post an inquiry about "nice things in your area" it was literally one of the only things people could recommend.

"Most of the city is a food desert and there's a lot of condemned buildings and heavy metal contaminated soil, but there's an annual Bluegrass concert and the bike trails are AMAZING."

~~-I'll add some further comments in a reply to this~~ actually, no. It's too long