Looking at safety without also considering utility is a bad move. If I want to be really safe, I should stay in bed all day. Merely going down my stairs is a

Looking at safety without also considering utility is a bad move. If I want to be really safe, I should stay in bed all day. Merely going down my stairs is a remarkably dangerous activity, yet I consider the utility to be worth it. Therefore the real metric to minimize is deaths per passenger mile. Or, even better, take into account the lifetime 'used' to get that utility. So maximize miles travelled / total time spent travelling and waiting at departure gates, where a death counts as 100 years.