Background NHTSA defines aggressive driving as "the operation of a motor vehicle in a manner that endangers or is likely to endanger persons or property." A popular stereotype suggests that some vehicles (body types or styles, makes, models) are driven more aggressively than others. Is that actually true? If so, are the differences "real" or do they merely reflect the demographics of the drivers? Finally, is there anything about the designs or performance of certain vehicles that motivates normally defensive drivers to become more aggressive?

Objectives Establish an estimate of aggressive driving rates by vehicle types. Quantify the aggregate number of aggressive-driving behaviors per vehicle year or mile (violations, culpable crash involvements, etc.) by vehicle body type and style. Disaggregate these aggressive-behavior rates by drivers' age, gender, and other geographic/demographic factors. For drivers who use two or more vehicles, compare their aggressive-behavior rates in the different vehicles - to see if the same person changes their driving style as they move from one vehicle type to another.

Proposed Approach Registration, licensing, violation, crash and possibly mileage (at inspection) data from one or more large States would be linked and jointly analyzed to compute aggressive-behavior rates by vehicle type and driver age/gender. Alternatively, one or more large insurance companies may be able to compute some of these rates from their files. If the data also specify drivers' ZIP codes, they could be linked to geodemographic data indicating average income, education, urbanization. The evaluation could take 2-4 years, depending on the difficulty of acquiring and assembling the data.