If someone was willing to invest into building and maintaining infrastructure there would be no need for this concept, but that’s a political issue. The idea of this concept is do make the best of what you have.

How would traffic pass each other? You would be stuck with the same issue as normal trains.

Hmm the prices on eBay really don’t seem that good to me in comparison to newer generations. I guess the power consumption will eat up any savings pretty quickly. Though this might differ for whole sets.