If I were utterly paranoid, I'd either drive every day (and stash a rifle in my trunk!) or not take this job. I'd abandon my career and move out into the back of beyond.

I'm not trying to prepare for a zombie apocalypse while I'm on the train. The two most likely versions of unpleasantness are a small-scale disaster, where if I survive professionals will come to my rescue, or a short-term transportation disruption, perhaps as bad as overnight. It's worth spending a few bucks and a few ounces of weight on preparing for a variety of contingencies, but I won't be bringing a hobo suit to use as urban camoflage.