Unless all your passengers need to go the exact same route, your efficiency calculations suffer because people might (and will) have to travel much longer distances because of the inflexibility of train networks.

@jahn True, and the same is applicable to autobahns too.

"Much better safety : in Switzerland 2017, there was almost 18k people wounded or killed by road, only 57 people wounded or killed by trains (excluding suicides), this makes road 312 times more hazardous than rail." Depending on passengers and miles travelled, your conclusion may or may not be true. Let's assume it is - what happens to relative cost if it is somehow ensured that road users bear full cost of the consequences of poor safety - e.g. if cost of hospitals for road accidents was fully recovered through a direct charge on road users, or via fuel levy?

I'm guessing that "anecdotal" is not what you mean here ("not necessarily true or reliable, because based on personal accounts rather than facts or research").

"in countries who sponsor their rail network..., rail transport decreased significantly since the 1950s": interestingly for the UK, this was true until the railways were privatised in 1995 - since when passenger numbered have more than doubled (source).

"Train passengers can have another activity during the ride, an option which is limited in road transport, even for passengers, as the comfort and space available is much lower." - No offense, but have you been on a train recently? Regular train seats in most of Europe don't offer enough space for using a laptop, let alone leg room or a cup holder. If you get a seat at all, that is.

Also, I've heard that other national railway companies have a better reputation, but Deutsche Bahn at least is widely known for their almost comical inability to cope with any sort of change in weather conditions.

@RutherRendommeleigh I use trains every day; and I'm sad to hear that trains in our nothern neighbour suck so much compared to ours... That's easily fixable through by changing the wagons for more confortable ones this is not a flaw inherent to trains.

@SteveMelnikoff Interesting, it shows that at least in this case privatisation can work well, but I heard it worked awfully in Poland. I guess it depends more how it is privatized.

@Bregalad: it depends a lot on how you define "working well"! It turns out to be extremely subjective, and hence this is a highly political issue in the UK.

Related: Are there countries with true open-market railways?

See A Pattern Language — Christopher Alexander: pattern 20 Mini-busses Summary-of-mini-busses-pattern. (The full text has more on the economics of the pattern.)

Related: Is there any evidence that public transport splitting, corporatisation or privitisation affects quality?

@SteveMelnikoff My take on "working well" in the UK means, as far as travelling to London is concerned, there's no other viable transport if you need to be somewhere at an exact time (such as work) so the rail companies can increase prices to make it profitable - passenger satisfaction doesn't come into it.

@Bregalad You take the autobahn as long as you need to and then get off and drive the rest of the way. And you can have options to get off every 10km, which you can't with trains (if you still want them to be effective and quick). Personal transportation is less effective fuel wise but often much more effective time wise. Example today: went to the beach in Germany. 75 minutes by car, trains run 2-2.5 hours with two change overs.

I think this question has too many questionable assumptions and debatable analysis to be a fruitful way to approach questions around the economics and politics of rail transport.

@DavidMuler's answer talks about the high cost of highways... which are not profitable at all but very prevalent. "Road travel is massively subsidised in the sense that the negative externalities of travelling by car, including the release of carbon dioxide and other greenhouse gases, are not fully offset, and most major highways—which cost tens of billions to maintain"

"rail passenger transportation is, in a purely engineering point of view, much more efficient than road transportation" - did you account for having to run rails down every street, and up everyone's driveway which would need switch gear about every 50 feet or so, and at every intersection (after having knocked down the four buildings at the corners to widened them)? Or are you comparing apples to oranges?

Interesting that "sponsored by governments" means paid by taxes taken from citizens (and corporations). So, you pay twice.

The real answer is a book-length publication like idei.fr/sites/default/files/medias/doc/wp/2003/… Both demand and supply for rail transport have complex economic analyses, which probably any SE site is unsuitable to provide. Voting to close as too broad.