I discounted the passenger version immediately. It is cheap, fairly easy and quick to transfer people from bus to rail. "Step this way ..."

Rubber tires will lose enormous energy carrying the safety requirements of passenger rail cars on freight lines. Just not practical to carry that much extra weight on rubber tires !

I could see the freight version having a niche market. No need for container handling cranes for intermodal access at small rail sidings. OTOH, excess weight and drag to carry the road wheels and axles along.

Universal shipping containers (8' x 8' x 20' or 40') are slightly undersized for the maximum allowed on US roads and much less than US railroad loading gauge (they are sized for the smallest allowed anywhere in the world, which is smaller than the USA). For domestic shipments, I could see value in larger inter-modal containers or equivalent (and Rail Runner would be equivalent).

Still the frames would be heavier than required for truck freight and this alone might kill it. Perhaps not a big deal for an 18 mile delivery run. I would like to see an American size (over sized) container be introduced.

So, interesting possibility for a niche freight market, but unlikely to be a revolution. No hope for passenger service.

Best Hopes for Good Ideas,

Alan