Some transport enthusiasts create fantasy rail maps, and while some of these may have merit, others are just railway lines going everywhere. I know these are usually not meant to be done in real life, they help in pointing out some problems in transport systems that aim to provide one-seat rides everywhere, especially on rail.
This part will cover cost and efficiency.
Cost is a quite obvious problem in these systems, as most of the services won't have very good patronage, and ticket prices would probably stay the same, so public transport becomes a huge part of the budget, in my opinion a waste of taxpayer's money. While it may be too much to ask for profitable public transport when the car competion is subsidised, that doesn't mean we shouldn't keep costs low and patronage up, especially in rail, where lower labour costs make profits not so distant.
Since these trains would have low patronage, the fuel economy would be terrible, even using electricity. Forget that public transport is better for the environment, if you operate a whole train for just a few passengers. However, some fantasy trains could work as bus routes, but this may still pose some problems, as I will explain in the next part of this subject.