Did CP and OVR make a mistake with removing the Chalk River Subdivision with all of the CP oil trains bound for eastern refineries now having to run via the longer run through Toronto?
I wouldn't think so. The OVR (what I'll use to refer to the CP Ottawa valley line) is/was in awful shape, is slow, and needs a cash infusion to operate something as potentially dangerous as solid trains of crude. The bean counters ran the numbers and it would seem obvious that going via Toronto is the cheaper route. There is likely no benefit to shaving five or ten hours off the transit time of a crude oil train in that the consignee isn't going to offer to pay more for the faster transit time. Railroads lost pretty much all of the time sensitive traffic long ago... all those containers aren't generating revenue based of transit time. The mileage increase is easily offset by the fact that it is cheaper to maintain one route over two, and the route via Toronto is not at capacity, so from an economic standpoint, there is no reason to seek another route. There will be investment in the current route to increase capacity by lengthening passing sidings to accommodate the longer trains CP is running now (awkwardly), something long overdue.
IMO, the OVR was doomed the second CN abandoned their Ottawa-North Bay through route. There was no longer any competitive advantage to the OVR in that while CP may have retained a shorter route than CN, CN gained the advantage of operating more trains over a single route, lowering their costs since they'd be maintaining the Kingston and Bala Subs regardless of the what happened in the valley. With the added traffic from the valley's abandonment, they earned more revenue to cover essentially the same cost of maintenance on the Kingston and Bala Subs that were being operated under capacity. It also gave CN the advantage of using trains more economically, in that a train out of Mtl could carry a western Canada block and a Toronto/Southern Ontario block to Toronto, set off the Toronto traffic and lift more western Canada traffic and continue on their way west. They did just that, and CP is now doing the same.
The OVR is like the CASO... great idea at one time, but outlived its usefulness.