In what they are calling the first study to systematically identify aggressive driving behaviors, a team believe they have measured the changes in driving that occur in an aggressive state.

Obviously non-professional aggressive drivers drive faster and make more mistakes than non-aggressive drivers, they put other road users at risk. They also pose a challenge to engineers working on self-driving car technology. UK officials claim that 80 percent of UK road deaths are “predominantly caused by dangerous and reckless drivers.”

There's no clinical trial for this kind of thing, we don't let aggressive drivers out on roads any more than we test the effects of psychiatric medication on likelihood of being a violent criminal, so in their place simulations can help. Participants were asked to recall angry memories, putting them in an aggressive state, while performing a driving simulation. These were compared to a control group, who weren’t feeling aggressive.

Aggressive drivers were identified as follows:

Aggressive drivers have a 5km/h mean faster speed than non-aggressive drivers;
Aggressive drivers also exhibit more mistakes than control groups – such as not indicating when changing lanes;
Aggressive driving is categorized as any driving behavior that intentionally endangers others psychologically, physically, or both.

“This research is significant because, as the era of autonomous vehicles approaches, road traffic will be a mix of both autonomous and non-autonomous vehicles, driven by people that may engaged in aggressive driving," says lead author of the study and University of Warwick PhD student Zhizhuo Su. "This is the first study to characterize aggressive driving behavior quantitatively in a systematic way, which may help the autonomous vehicles identify potential aggressive driving in the surrounding environment."