Correct, and the DRZs (directional routing zones) were formed without any government intervention, formed merely from the realization that splitting traffic over parallel tracks by direction rather than company would result in a win-win-situation where both companies reduce cost (by requiring less sidings), while operating faster (no need for train meets).
With CN already owning a double-tracked ROW between Montreal, Toronto and London, it will be very difficult to compell it into any track-sharing agreement with CP…
It's worth delving into why coproduction might or might not help VIA in the corridor.
One scenario is having CP and CN share parts of the CP line for freight and thereby free up the CN line for VIA.
Another scenario is for CP to move on to parts of CN and VIA takes the CP line.
A third is true DRZ where one line is used for all trains in one direction and the other line for the other direction.
To impose any of these between Windsor and Quebec - In all of these, Ottawa would have to work through
- the lengthy and likely litigation-necessary exercise to define the compensation to each railway to let VIA "buy in" ie taking assets away from private owners - to date, coproduction only involves the railways "sharing" assets between themselves
- the need for the two railways to sort out a mutually-beneficial operating plan for both through trains and service to online customers
- the need to ensure competitive equity (ie preserve or compensate for any competitive advantages that either railway has today)
- the question of how well that new plan actually meets VIA's needs or enables improvements
- the cost of civil works to connect the two lines, and add any yard and passing tracks required
- the cost of moving any VIA stations
- the cost of moving or replacing existing yards
- the need to preserve ling-term freight capacity for future growth
While there is currently a huge oversupply of freight capacity in this corridor (which intellectually one thinks ViA ought to be able to leverage), given all the above headaches, finding a new corridor for VIA is simpler and faster. It's being pragmatic.
I have to nitpick with
@DirectionNorth's comment that there will never be another new rail corridor along the Lakeshore. These things do happen in other countries, but with extreme cost, excruciating slowness and huge cumbersome public consultation processes. It's a good thing for Canada that for now, Ottawa can sidestep all of that by leveraging the cheap undeveloped real estate in the Shield. Where new lines are being built through denser areas (Recent Examples include UK, Belgium, Italy and of course the older TGV Spain etc) the rationale that overcomes the public and political opposition has been is, the existing lines are tapped out and not building would have unacceptable impacts. Canada can't make that argument there yet. But I continue to believe that Ontario and Quebec should be building added rail capacity into municipal zoning and urban plans.
- Paul