A fender-bender in Roswell, Ga. could have had fatal consequences over the weekend.

After a car backed into his wife's SUV, a man went to confront the driver who allegedly caused the accident, according to ABC57-TV. Instead, she sped away – with him on the hood. She drove approximately two miles with the man clinging to the windshield wipers.

"A car could have trampled him, and he could have died," his distraught wife, Theresa Kim, told the television station.

Police have not yet located the driver. They say she faces felony aggravated assault charges.

What is road rage exactly? Usually, it is a momentary emotional response to a trivial situation while in the car. But it can also be when someone decides to take out their aggression on another person using the car as weapon.

Road rage incidents are hard to quantify and study, but experts suspect they are on the rise. A survey from the Automobile Association Driver Education Foundation asked respondents how they felt "behavior of motorists" had changed in recent years.

Sixty-two percent said it had become "worse," while only two percent said "better." Thirty-four percent said it had not changed.

In a recent survey, conducted by the AAA Foundation, of 3,147 American drivers, 55.1 percent of respondents said that aggressive drivers are a "very serious" threat to their personal safety and 33 percent said they were a "somewhat serious" threat.

Traffic experts struggle to produce hard-and-fast road rage statistics, because measuring the intent of motorists to injure their fellow drivers can be difficult. Most studies attempt to measure road rage using aggressive driving statistics, but their criteria, too, can be hard to agree upon.

Incidents have become frequent and bad enough in Michigan that the state has been messaging "Prevent Road Rage. Don't Engage" on highway digital signs around metropolitan Detroit.

Pegging reasons for a rise in road rage is very tough. Some law enforcement and psychologists point to economic stress on more people these days due to unemployment and under-employent, as well as the left vs. right political/cultural divide in the U.S. that seems to be exploited and fed by the media and political campaigns on a daily basis.

Road Rage Often Kills

Aggressive driving can be measured from the obvious – making rude gestures, tailgating and honking the horn – to the more nebulous – such as driving 10 miles over the speed limit.

Another study from the AAA Foundation analyzed more than 10,000 suspected road rage incidents over seven years and found they resulted in at least 218 murders and 12,610 injuries.

The reasons for the incidents were "often trivial," according to the study. When drivers explained why they became violent, they told researchers, "she wouldn't let me pass," "they kept tailgating" and "he practically ran me off the road – what was I supposed to do?"

According to the study, 37 percent of the violent incidents involved use of firearms, 28 percent involved other weapons and 35 percent involved the use of the car itself as a weapon.