I think the general principle is that the less control you personally have over the means of transportation, the more liability rest with others, and therefore

I think the general principle is that the less control you personally have over the means of transportation, the more liability rest with others, and therefore the more checklists, procedures, and redundancies there are in place to protect you. Very safe: trains and subways, buses, passenger aircraft, rollercoasters, elevators Very unsafe: personal automobiles, small aircraft