Hmm. From what I've heard of air rage incidents, very often these correspond to alcohol consumption, not smoking or lack thereof. Although having been around alot of smokers, I can see how nicotine deprivation can lead to shortness of temper, irritability and potential explosions.
As for road rage...got me there. I think the rise in road rage incidents is related to increased stress in everyday life, as well as lack of stress-relieving activities in most people's routines. I think if we all got more vacation time from our jobs and took a bit of exercise to boot, not only would we be in better shape, we'd be alot calmer!