Here is what I can tell you about accidents involving human factors. The board determined that about 20% of accidents involved fatigue. That is why, in October 2016, we put fatigue on our latest watchlist of key safety issues for freight train crews.
That being said, whether or not an accident occurs, oftentimes video or voice recordings can reveal what the crew members were doing earlier and whether they had sent signals, whether they were talking and whether they were aware of signals they were receiving. That information helps the TSB identify safety deficiencies. If companies have access to that information, they can introduce training measures and adopt better procedures, which may not have prevented the accident that just took place, but will prevent other accidents.