A theory about road rage

On the weekend I ran (jogged) in the Mother's Day Classic, which is a 5km fun run to raise money for the National breast Cancer foundation. Although this is an excellent cause, I still really have a problem with this concept - actually, both concepts : breast cancer and fun run. Breast cancer is fairly obvious but the whole idea of making a run "fun" was only dreamed up by people who bound out of bed at 6am with their sneakers already on and take off for a "little" 10km jog whilst hearing the "Chariots of Fire" music in their heads without the benefit of an ipod. I suppose it is bad marketing to say "come and inflict at least some discomfort on yourself to raise money for breast cancer funds", but isn't honesty the best policy? I suppose I prefer to delude myself most of the time, so I am a good one to talk. Anyway, an incident occurred during the run that has got me thinking about why drivers get so soooooooooo fricken' cranky on the roads. My dad and sister also ran in this and as my dad was coming up to cross the road (which had been closed and widely advertised that it would be closed for this event) an upstanding young gentleman in a white ute was arguing with the chappie with the "stop" lollipop and claiming his god given right to drive like a moron on this particularly fine Sunday morning. The lollipop guy was putting up a fairly stoic and considered debate to this view (I believe moron ute driver was told to "calm the frick down") and finally, ute moron guy snapped, jumped into his great white symbol of testosterone blokiness and DROVE THROUGH the runners who were crossing the road, blaring his horn and waving his fists. God knows what he was actually steering the car with, but I think we all know that it wasn't the big brain making a lot of his decisions, given his previous behaviour. This was followed by an experience of my own yesterday, where someone tailgated me all the way into work up Limestone Avenue and resorted to obscene finger gestures when I chose to ignore her polite suggestions that I just run over the cars in front of me. Now, I don't know exactly what is going on to cause all of this tanty behaviour, but I have a few theories.
1) Basic anatomy. For some people, when they get in their cars, they end up getting a bad wedgie every time. I think we've all been there at least once and let's face it, if this happens on a regular basis, you are going to be a little short tempered. And as they are obviously too much of a lady or gentleman to remove their undies from the area where the sun doesn't shine, it is much better to get angry and shout obscenities at other drivers on the road.
2) They have the BEST JOB IN THE WHOLE WORLD!!!!! Now, I like my job, I really do. However, if the traffic is bad on a particular morning, the most I feel is mild exasperation that I may get to work a bit late and have the park where the birds will poop all over my car during the day. Obviously, the people who completely FLIP OUT when you are 3 seconds too slow off the mark when the light changes green have THE BEST JOB IN THE WHOLE WORLD. The anger they feel that precious seconds will be lost at work is just too much to bear. Understandably, if you have THE BEST JOB IN THE WHOLE WORLD, your emotional outburst where you cast aspersions on someones genetic heritage loudly out of the car window is quite justified.
3) People who inflict road rage on other drivers are nobs. I like this theory.