A minor fender-bender left two motorists uninjured along a Houston highway earlier this month. The argument and shooting that followed left a young man brain damaged, possibly forever.

It's an all-too-common road-rage scenario, police say. Overworked commuters, under-employed workers, road construction and radio talk shows seemingly designed to get drivers riled up. It all contributes to hot-headed driving.

And it happened to Gary Harrell last month. Following a fender bender, Harrell and the other driver bickered back and forth for several minutes from inside their respective vehicles. The argument escalated. Harrell pepper-sprayed the other driver, who responded with gunshots, one of which hit him in the head.

Harrell's mother tells the Houston Chronicle her son speaks like a child now. "I'm angry and hurt because my son has to go through something over such petty stuff," she tells the newspaper.

Over the past five years, road-raging drivers have caused more than 900 accidents that have caused at least five deaths in the greater Houston area, according to Texas Department of Transportation statistics.

Firm statistics nationally are difficult to pin down. But in 2011, CNBC named New York the nation's worst place for road-rage incidents, followed by Dallas, Detroit, Atlanta and Minneapolis in the worst five.

In another Houston case outlined in the video above, Jonathan Darling 28, wound up in a physical altercation with another driver. The other driver died during the altercation, and a grand jury investigated whether Darling, who told police he was defending himself, should be charged.

Harris County law enforcement says they receive approximately three or more 911 calls per day detailing road-rage incidents, including aggressive driving, vehicles chasing each other or cutting each other off.

Why Road Rage?

Traffic congestion in the Houston area is one trigger for such incidents. A survey conducted by AutoVantage in 2009, which did not include Houston in its top-five worst cities for road rage, ranked Houston second in the number of drivers reporting their fellow motorists for speeding.

A recent survey released by Response Insurance showed that 34% of drivers honk at aggressive drivers, while 27% yell and 19% flip the finger. Just two percent of respondents say they have tried to run an aggressive driver off the road., but that is probably an under-reported number.

Different surveys give both men and women the edge in being aggressive drivers who have instigated driver-to-driver altercations, probably meaning men and women are split down the middle as instigators. But the Response survey showed a clear trend of young people (67% of those 18-24 said they are more likely to respond to an aggressive driver with aggression) versus just 30% of drivers 65 and over.

Perhaps the most surprising finding: that 59% of respondents with children said they were more likey to response with aggression to an aggressive driver. AOL Autos expected that parents with kids in the car would either be more mindful of starting an altercation, and wouldn't want to model aggressive behavior.