Well we already have a lot of those, at least in North America (best freight rail system in the world), and it might make sense to build even more tracks in some areas. But rail will never be practical for time-sensitive cargo. It just takes too long to assemble a train and move cars through switching yards. We're always going to need a lot of trucks no matter what.

Any sufficiently method of ground transportation contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of a rail network.

Truely rail-fans are transportation equivalent to vegans in food or cross-fit in exercise. I've spent many an hour on the Isle of Sodor and appreciate how useful those engines are in so many contexts. Yet still, there are buses that move alongside Percy, and pick up stranded passengers, and the Fat Controller (aka Sir Topham Hat) still has a sedan. It's a multi-modal world out there and the tractor trailer still has a place in it.