Fully building out a 2nd set of dedicated infrastructure doesn't seem efficient. I think it would be far less expensive to have a neutral 3rd party of engineer

Fully building out a 2nd set of dedicated infrastructure doesn't seem efficient. I think it would be far less expensive to have a neutral 3rd party of engineers, economists, and finance folks figure out a way to compute the cost of demoting freight to 2nd billing. And then by law require passenger service to have priority, and to pay for it, while having safeguards for either party to game the system, with on-going audits. This might be a kind of taking of private property for public use, which is allowed by the fifth amendment so long as there's just compensation. Whether sections are leased or bought can be a point of the negotiation. But using existing infrastructure is inherently more efficient so long as there aren't already congestion problems. And where there are congestion problems it makes sense to mitigate those locations.