The Railway Association of Canada says that more than half of the country's exports are moved by rail, in addition to 70% of its intercity surface freight.
Ahead of looming deadlines, it's unclear whether either situation will resolve in time to avert these twin crises, or how long any potential work stoppages might last.
There have been and will always be threats to the supply chain, and companies will always be managing moment-to-moment changes in the economic environment.