There's more than one purpose for it. That is one purpose, for sure: to be able to review what happened in the case of an accident, as we've seen many cases where there are serious accidents, particularly where there are fatalities. I can think of one from a few years ago—I think it was in the Brampton area—when all three people on a locomotive were killed. It was very difficult to determine what happened in that situation. Certainly, the Transportation Safety Board would want to use that information in investigations.
On November 9th, 2017. See this statement in context.