Its been proven that if you are an agressive type of person, You will be an agressive driver! Many who are agressive and impatient at driving are also like it in everyday life eg the person who is fed up at beung third in the queue at a checkout for instance, The person who shouts and screams alot, The person who becomes confrontational over things instead of just walking away.
Aggression and behaviorism are both aspects explored and defined in psychology and behaviorism. Psychologists have the ability to assess particular tendencies, impulses and behaviors in all types of situations, including riskier, high-pressure ones like driving. It's also likely that kind of behavior pops up in other stressful areas of an individuals life.
In order to make a viable research study, a researcher might want to interview a number of drivers about their driving experiences and their opinions on other people's driving abilities. This interview might give the researcher an idea about the types of driving encounters that occur. Then, the researcher could create a categorization based on which behaviors the participants considered to be more aggressive and which they considered to be more obnoxious.
It is certainly possible to categorize drivers by conducting thorough, scientifically sound research. Research already shows that young male drivers have a higher incidence of accidents and aggressive driving, while females show less of this behavior. Therefore, additional research may show other categories that make it more likely for a driver to behave badly on the road.
I don't know how you would even conduct this research. Would you put microphones in the cars? What would be the control? It seems like a great topic to look at objectively to find out more. However, I just don't see this working in a reliable and practical way myself.