If we're talking about land, then why not have the government negotiate some kind of "land swap" deal with CPKC?
CPKC gives the government the midtown line, Agincourt yard & Lambton yard. The government in return gives CPKC an equal amount of crown land to construct a freight bypass and a new yard outside the city. Perhaps a bypass running alongside the proposed 413 highway?
Realistically, the only new line that CPKC (or any other investor owned railway, lets not demonize CPKC here) would easily accept in trade is one that runs in a straight line, downhill in both directions.
Trying to quantify whether a new line is a good deal has many variables....the biggest likely being, how do the shareholders feel. The original Halton bypass was shorter than the existing line, had lesser grades.... but CN still was not interested. The devil you know, etc.
We don't know what numbers CPKC would put forward as their view of "just" compensation, I'm sure that they would have a very large number that reflects some of the principles of fair market value and profit in perpetuity. The current legal regime probably would respect some of that.
Still, it's worth having a regulatory model for shared use that is applied across all rail corridors. To repeat, the key interests for the freight railway are to continue to operate efficiently (with both track capacity and operational control), and to be able to meet future growth. They would need to retain line of sight to the physical assets and past investment they have made, and know that transit was not making uncompensated use of these. If these interests were satisfied, I'm not sure that the expropriation value would have to be much higher.
I would not apply current "market value" to land - much like a pension plan, a railway corridor has a going-concern valuation and a windup valuation. I would not pay CPKC the "potential development value" for property that is going to be a rail line for the next 999 years on the premise that they could tear up the tracks and build condo's (yards and other property may be a different matter). Their public franchise is based on their commitment to running trains if the economic conditions are sufficient. And like any land use decision, government holds the authority to "zone" land as a rail corridor and decline to "rezone" as mixed use.
The question is, do we want to spend a decade in the courts to work this out. A legislative push that ended up in court might be politically possible provided that the construction could proceed. It's a lot like buying back the 407 - potentially costly, but not necessarily bad business for the Province in the long term, if you can push the cost off to some future government.
- Paul
PS - Whose rail name appears on title is a fascinating subject. It's amazing how many old corporate railway names pop up when land transactions happen. While some consolidation has happened, there are still lots of examples where old corporate identities have been retained because of some condition in the original charter or some money issue.