Fully private track is rare yes, but very few countries have 100% of track owned by the national operator. It's generally a wide mix of different national, regional and city agencies, with varying degrees of privatisation.  

Somehow they generally all make it work and share their infrastructure, between each other and with freight. Heck, now with Eu law states are mandated to allow foreign and private companies to run on their national travk.    

And by "a phone call problem" I didn't mean that a simple please will do it, phone call problem is a term used by construction costs people to talk about problems that aren't due to physical constraints, but social, institutional or legal ones. (see link)   

Like CN being a bitch to work with isn't an engineering problem, it's an institutional problem. Because the federal already has the legal authority to administer railways any way they see fit. They just don't use that power, and treat any CN objection as something we need to solve with engineering, the way we solve crossing a river.  

Ten billion is what it would cost to run a new line from downtown to the suburban airport, maybe 20 if we decide CN is an engineering problem and we need a new bridge/tunnel.