"If one more idiot cuts me off," screams Uncle George, "I'm going to run this car right up his but." We're on the Gardner Expressway in Toronto, at rush hour, trying to get cross-town and Uncle George is having a Tourette driving moment.

The brake lights on the Lexus in front of us flash on and Uncle waits to the last second to slam on his brakes. I can see his lips moving as he cusses to himself and his hand hovers over the horn, itching to express his disappointment with the other guy's level of driving competence.

He resists messaging the Lexus, perhaps because earlier that day I'd read him an article about two guys in Miami, who got into a road side beef and called on Mr. Smith and Mr. Weston to arbitrate their disagreement. Eight gunshots and two fatal wounds later the dispute ended in a draw.

To the best of my knowledge Uncle isn't packing, although I can't speak for the guy in the Lexus. But these days it's best to expect the least possible civility when communicating extra-vehicularly, with any ill-humored motorist you encounter on the road.

So how come vigilante behavior has become so pervasive on our roads, with an almost culturally sanctioned view of highway hostility. Naturally nice guys like Uncle, who'd buy you a beer and chew your ear off under other circumstances, get behind the wheel and throw a tantrum, Mad Maxing every stranger he sees.

And it's not just a guy thing anymore. Women have embraced the asphalt culture of disrespect. They've learned to uncage their rage and participate in the current orgy of furious driving. The whole highway community seems to have embarked on a collective, cross gender, mental health melt down.

Sure, we are all a lot more uptight these days, no doubt about it. We're living in a culture of dissatisfaction. Everything seems to be going faster and faster, the boss is mean, the bills pile up, terrorists lurk behind every gas pump, the kid cries all night, and the partner has a headache from June to December.

But to come right out and aggressively confront a stranger over his apparent lack of respect. What is it that angers us when the guy in front doesn't leap into the intersection the nano second the light changes? We don't freak like that in other parts of our life. "Hi Joe, want to buy some widgets? No! Well screw you, ya stupid jerk!"

Sometimes it seems like everyone's gone nuts on the road. There is a spot on the 401 near Pickering where, coming into Toronto, you pass under zillions of high tension wires sprouting out of those mini-Mount Saint Helens reactor bubbles, down by the lake. It's like there's a force field right there on the highway and as soon as you pass through the guy behind you tries to check your prostrate and every thing suddenly takes on the feel of a high speed chase.

Let's say you're late for work. You're in the passing lane when this jerk pulls out in front of you. His old beater needs new rings and he's got it floored, but it isn't enough. You come up behind him, flash the high beams and shoot him the bird. He retaliates by hitting the brakes. You spin out and end up in the ditch with totaled wheels and a fractured clavicle. All that mayhem and carnage because you thought you were going to be late for work. Well now you are late!

In most other situations we restrain our disappointment and aggression, sublimating it into more socially acceptable behavior. We bad mouth our friend behind his back and surreptitiously cheat on the partner, with her best friend. But all the while, out in the community, we maintain the social patina of civility and composure.

Here's one theory about what's going on. We as motorists interpret the things other people do, getting from A to Z in their own idiosyncratic manner, as being about us. We personalize it. Like when Bone Head Bob got up this morning the first thing he thought about was how to make your life miserable. The guy in front of you hits the brakes and you think he wants you to rear end him. He turns without signaling and you think, "My god, that idiot is trying to kill me".

We take it personally because at some level we all see ourselves living a movie, written by us, about us, and starring us. And this depersonalized extra in the other car isn't following the script. He thinks he's the star and this movie is about him. Well of all the nerve. I'll show him.

Driving is an autobiographical act. A statement about where you are and where you're going in life. An affirmation of being. And anyone who interferes with your journey is interfering with your life story. "So get out of my way goof, I've got somewhere to go, and a big scene coming up."