For each one of those topics, remote control devices, fatigue, etc., there are so many witnesses who could speak to those that it would be difficult to organize meetings by subject. I would suggest organizing meetings by witnesses, and yes, asking them questions on all of the subjects before the committee.
I do recognize that the work looks very broad with the four topics, but two of them are really only for Transport Canada: checking up on their progress on their commitments to the committee's last study, as well as the 2007 Railway Safety Act review, and that's a pretty limited topic that could be dealt with in one meeting.