1. Motorists with guns are more likely to act aggressively (Arizona)
Using data from a telephone survey in Arizona, we examined the relationship between road rage and gun carrying in motor vehicles. We found that self-reported hostile actions (e.g. obscene gestures, cursing or shouting, aggressively tailgating) were more common among men, young adults, and individuals who carried a firearm in their car.
Miller, Matthew; Azrael, Deborah; Hemenway, David; Solop, Frederic I. Road rage in Arizona: Armed and dangerous? Accident Analysis and Prevention. 2002; 34:807-814.
2. Motorists with guns are more likely to engage in types of road rage (USA)
Over 2,400 licensed drivers responded to questions about their own aggressive driving in a 2004 national random digit dial survey. We found that 17% of respondents admitted to making obscene or rude gestures in the past year, and another 9% admitted to aggressively following too closely. Males, young adults, binge drinkers, those ever arrested for a non-traffic violation, and motorists who had been in a vehicle in which there was a gun, were more likely to engage in such forms of road rage.
Hemenway, David; Vriniotis, Mary; Miller, Matthew. Is an armed society a polite society? Guns and road rage. Accident Analysis and Prevention. 2006; 38:687-95.