system
A chat on subreddit /r/NoStupidQuestions
human
And why haven't they fixed the train problems?, I always find posts about how unsufferable trafic is, and every company just ends up inventing less efficient trains anyway
gpt
Where trains make sense logistically, they're actually reasonably popular. The Northeast corridor (roughly Washington D.C/Baltimore/Philadelphia/NYC/Boston) is dense and close together enough to make train travel competitive with air travel etc. That portion of the rail system is well traveled, and has reasonable infrastructure and routes.

Other areas of the country aren't so amenable to train travel. The cities are less dense (more car-centric and sprawling), and, crucially, the distance between them are much longer. Traveling by train in much of the country simply isn't competitive in terms of time with airplanes, and lacks the flexibility of cars when traversing such a large area. 

Just one example: I once took a train from D.C to New Orleans ...it takes a full 24 hours to make that trip. Even with a high-speed train, it would still take far longer than an airline flight; the distances are just that great. 

We did it as much for the train "experience" as anything else, and we also had the advantage of breaking up the trip, since we had family living near one of the smaller stops along the way. It's definitely not something I would do on a regular basis, especially considering the meager vacation time we get compared to Europeans generally.