It’s been assumed, since trains were invented, that they would be giant, friction-driven monsters made of cast iron and brass.
Today’s invention revises that idea…by suggesting (again) that the existing tracks be used to carry micro-carriages.
These would flexibly transport small freight packages (maybe as small as a suitcase) and would run on only one track at a time. This would avoid all the nightmarish scheduling issues to do with having thousands of two-directional trains vying for the same track space.
Each small carriage would be made of lightweight materials and be individually driven by a small gas turbine -or even a modern steam engine with a low pressure jet exhaust (anything other than rail friction -maybe even mag-lev?).
What happens when vast numbers of these are heading for multiple collisions across the network? Well, each would also carry a lightweight sigmoid-shaped bridge rail. When a collision is predicted, the carriage would lower its bridge rail section to one side of the track and either park itself momentarily, in its own mini siding, or place it between the tracks in order to swap rails.
This approach would also allow all conventional rail traffic to continue on its merry way as normal.