• PDF format (Read on any computer using free Acrobat Reader)
• HTML (web) format (In your browser--like the current page)
• Word 6.0 (95) format (Opens using Microsoft Word)

"A driving behaviour is aggressive if it is deliberate, likely to increase the risk of collision and is motivated by impatience, annoyance, hostility and/or an attempt to save time."


A driving behaviour is defined as aggressive, when the normal physiologic response to surprise on the road to the acts and actions of other drivers triggers the “startle response” and is seen to be deliberate rather than a bodily protective response to ‘fight or flight’. The parallel emotions of impatience, annoyance, hostility are seen to be motivators, rather than normal physiologic ‘irrational’ responses to those acts or actions and other situations along the pathway. The feeling of ‘urgency’, indeed of terror at being late building up within the nervous system with it’s impending latent ‘explosion’ is said to be a motivator.

While I agree with the overall premise of the paper, I don't fully agree with the definition of "aggressive" driving. In reality there is reference to 3 types of actions. The first being aggressive (e.g. horn honking, yelling etc) which are intended to harm physically or psychologically. Assertive behaviors (e.g. speeding, weaving etc.) refer to time urgent and "me first" oriented behaviors. While they are dangerous, illegal, and quite frankly stupid, they are not intended to do any harm. And finally, there are violent driving behaviors (e.g. fighting, shooting) which are intended to harm, but also to create a sense of power, control, and gratification in the harm of others (this is mostly what is reported as "road rage").

The use of "aggressive" is often confounded by "assertive" actions. This really limits our understanding of the potential link between true aggression and collisions, violations etc. in survey research (i.e. the lack of solid construct validity). However, this is not limited to driving research, but also common in personality research that describes outgoing assertiveness as "aggressive" when there really is no intent to harm.

I have been wanting to address the definition issue as well. There clearly is a bit of "apples and elephants" in these rather broad definitions. Of course, there might in principle be some use in such a broad definition; by analogy, I suppose apples and elephants are both life forms (or parts thereof), and there is likely some pragmatic value in biological taxonomy for defining them as such together.

I have yet to see a convincing argument that such practical value attaches to an inclusive definition in the case of all forms of undesirable driving being labeled aggressive. Does it help us improve driving better than would just calling it bad driving, or driving resulting from a "bad attitude". I would be interested in thoughts from those who are better able than I to work this out. I hope there is more pragmatic value than simply to serve as a smoke screen to cover the withdrawal of police enforcement resources to other priorities.

Larry

Larry:

I have tried to develop a more precise definition of aggressive driving which moves beyond "bad driving." The idea that this work is a "smokescreen" for anything is entirely unfounded. Let's get back to the question of defining aggressive driving. I think that gaining a clearer, common understanding of this risky driving behaviour is worthwhile.

My definition focusses on deliberate and willful driving behaviours that while not intended to physically harm another road user, show disregard for their safety and well-being. I have tried to introduce some notion of the underlying motivations for these behaviours, namely, impatience, annoyance, hostility and/or an attempt to save time. While referring to motivation is not strictly "behavioural", I think it is at least worth discussing the role of the driver's underlying motives in this context. The definition I've proposed would, for example, rule out lapses and errors that result from inattention or fatigue. I suspect that drivers who display aggressive behaviours behind the wheel are generally drivers who "know better", but decide that their immediate needs on the road supercede those of other road users.

There is, of course, plenty of room for discussion here. Some exploration of Dwight Hennessey's distinction between assertive and aggressive driving would certainly be worthwhile (see also his comments in the general discussion area).

Leo

Your very thorough review leads to a suggested definition that touches on several areas of psychology--perhaps too many at once. When I think back to my teens when only recently licensed, I recall driving at great speed down the highway. I was not drinking or drugged, but certainly was "high" on the exhilaration of driving fast, and on the reality of driving at all. The freedom and sensation of the experience resulted in a big grin on my face.

According to the proposed definition and its lead-up, I "showed obvious disregard for other road users" as I weaved along the road. I was also surely increasing all of our "risk of collision." But my actions were NOT motivated by "impatience, annoyance, hostility, or an attempt to save time." It was simply a blast!

Maybe my crazy driving was "intimidating or perceived as dangerous to other road users," and probably even "irritated or angered" some of them. But how do I know that for sure? We cannot survey them for their opinions. We thus are forced to measure their interpretation of my wild ride through our own lens. The question is, whose lens?

In reading over Leo’s rejoinder and my hastily-drafted comments on the definition question, I think my comments were perhaps, well, too hastily drafted, and not fully clear. In a hurry to initiate further definition discussion, I crunched up the whole, complex question of enforcement levels and their potential relation to aggressive driving into a shorthand form, using the perhaps ill-chosen metaphor of the smokescreen. I did not mean to suggest that there is some sinister agenda behind legitimate concerns with aggressive driving and any possible increases in it. I am, however, concerned with the mysterious drop in enforcement in my own province and perhaps in some other jurisdictions (see my conference paper). Certainly a major reduction in enforcement could contribute to an increase in aggressive driving, assuming an increase has occurred, but there are other systematic changes that could also contribute, such as increased congestion and perhaps even good economic times (when, as Gerry Wilde would say, time is even more money).

However, we need also to be mindful of the historical tendency in road safety to focus too narrowly on the individuals manifesting a problem and to ignore system deficiencies that might be contributing. If drivers are more aggressive in part because of a reduction in enforcement, it would be good to know that. Restoring traditional levels of enforcement might be part of the solution. Starting with Jim O’Day’s work in the 60s, we have been struggling steadily with managing road safety as a comprehensive system, which is essentially the difficult problem of looking at the micro and macro scales at the same time. The Haddon/Nader branch of road safety pretty much gave up on the individual, micro-scale concerns altogether, in favour of fixing the macro system (or at least some obvious physical parts of it), and I think we are reaching a point of diminishing returns from the passive part of the systems approach. It is past time to find better ways to understand and manage the micro-scale performance issues in individual drivers, but within the context of the system in which they operate. We have to think about both individuals and the system. We cannot focus exclusively on individuals and let parts of the system deteriorate out of sight and mind (or, as I loosely suggested, behind a "smokescreen")

As to the value of an inclusive definition of aggressive driving, I was again perhaps too hasty in trying to stimulate some thought and discussion on this important topic, when I myself did not have time to do it justice. The search for common factors among apparently diverse phenomena is a perfectly legitimate intellectual and policy-analysis pursuit. To the extent that we can find a common motivational basis for a number of different aspects of undesirable driving behaviour, all to the good. Then we would have a chance of treating them with a common intervention. I fear that we will not be able to carry this as far as we might like with aggression as a motive, but I could be wrong. On the one hand, I can see a clear need to nail down a manageable model of what motivates unusual or extreme driving behaviours that are thought to be especially risky. On the other hand, I can also see a wide range of motives that might lead to the very same action or to actions that look pretty similar. A lot of fast or erratic driving is probably done simply "for the hell of it."

We also have to be clearer about what we mean by aggressive. In common parlance we use it in at least two rather different ways. One is related to aggression, in the sense of behaviour that is manifestly hostile, threatening, or injurious. In drivers we could see this reflected in a wide range of actions, from lunatic road rage to the mildly rude, anti-social, or unhelpful. However, we also speak, say, of aggressive investors or aggressive skiers. In this usage we mean something more like active or assertive, or in more extreme cases, perhaps something like "voracious," with no connotation of aggression in the hostile or injurious sense. Indeed, in this sense the actions are not even transitive; there is nobody as object or "victim." In drivers, this could be driving 30 kliks over the "number on the sign" with nobody else in sight. Is there sufficient commonality that we could treat these two forms of aggressiveness with the same intervention? Perhaps, if we take Sarah’s conference paper literally (or perhaps with tongue in cheek) some sort of hormone therapy would help. I fear there is a wider range of critical motives at work, but maybe a two part typology would be a compromise.

Scott Geller would like us to focus our risk reduction motivational efforts on "active caring" for others, seeing correctly that personal risk reduction is often a hard sell. Scott has shown considerable success with this approach in industrial safety. It does seem easier for many people to change their behaviour to protect others than to protect themselves, and it seems that they often respond to efforts to encourage them to be more mindful of others. As Gerry Wilde has been pointing out for so long, we all can pretty well choose our own level of risk, as we carry around our own physiological "risk meters" in our chests and guts. We may need some help, however, in developing insight into the risk meters of others that we may be responsible for driving to uncomfortable levels.

Leo’s paper proposed increasing risk for others (or at least failing to consider them adequately) as part of the definition of aggressive driving. My first reaction was to think that all driving puts others at risk. This is logically correct, since I can hardly drive in such a way as to make other road users safer than if I wasn’t there. Surely others are safer if I leave my car in the garage and stay home, however skilled and careful I might be. But perhaps this logical truth is psychologically meaningless, or at best unhelpful. Following Scott’s lead, we have tried hard in our driver education work to emphasize a focus on: 1) the wellbeing of other road users; and 2) the expectations of other road users, and I believe this approach holds promise. Maybe this is an area where aggressive driving concerns and other motivational approaches can start to converge. If we had drivers out there "actively caring, " interprsonal aggression and aggressive driving, however motivated, would hardly be an issue.

Leo:

You have come very close to a definition which we were centering on in Washington, DC. What was important in developing a definition was 1) others had to be involved, and 2) simply adding together traffic violations, while it makes the policemans' lot a hapy one, is noit necessarily aggressive driving. In the latter case, one can develop many scenarios where drivers are committing multiple tarffic violations (it happens every day on our expressways, but the ordinary driver would never consider them aggressive). Likewise, there are actions which are clearly aggressive that may not claerly break laws, or at most break only one law.

Larry,

Thank you for a very thought-provoking response. I think your distinction between micro and macro level approaches is an important one. We have certainly focussed on the individual in road user safety. This is linked to the findings reported in classic studies on the relationship between driver performance and collision involvement. The most comprehensive and frequently cited study ever done on the role of the human factor in motor vehicle collisions is, of course, the Indiana Tri-Level Study (1977). This study, as you know, is based on 13,568 police reports, the on-scene investigation of over 2,258 collisions and in-depth investigations of 420 collisions. The Investigations were conducted by teams of trained technicians. The Indiana Tri-level study showed human error (defined broadly) was the sole cause in 57% of collisions and a contributing factor in over 90% of collisions. While the context of the system within which the individual drives must be considered, there is still much to be gained by ensuring that drivers are made aware of safe driving practices and taught that the well-being of other road users is their concern as well. I know you have approached this issue in a very systematic way in your excellent work on driver education. The goal should be to increase the number of drivers who see driving as a cooperative and not a competitive game. We haven't really discussed the potential role for social marketing/public education initiatives designed to promote responsible, cooperative driving behaviour. This could be another macro-level response to aggressive driving behaviour.

With regards to the value of defining aggressive driving, I'd like to refer everyone to the comments posted by Richard Wark and Richard Raub in the General Discussion Area under the title "Defining aggressive driving." They provide an overview of a recent National Research Council workshop on aggressive driving and discuss the role of a more comprehensive definition.

Leo

I was interested to see Larry linking the deterioration in driver behavior to the reduction in enforcement. This has also been my observation in New Zealand. When I was a Traffic Officer in the mid-seventies I was expected to visit and monitor compliance of every STOP sign in my patrol area at least once each week. It would now be about 20 years since I last saw an officer doing that. I believe the sequence of deterioration goes like this...
A driver sees another driver (most likely a commercial courier) failing to comply with the stop sign and nothing happens. After several such observations the driver says to him/herself "why should I stop when no one else does?" This may or may not be a conscious thought. They try it - and nothing happens! Another driver follows their example and the result is like a chain reaction. As long as the motoring public feared the financial and social penalties of being branded an "offender" this escalation was controlled. With the reduction in enforcement that fear, and the control it had, was removed. Compliance with stop signs in New Zealand is now so low I wonder why the roading authorities persist in using them!
This is not to suggest, however, that all our problems would be solved if we just returned to the seventies level of enforcement. Coincidental with the development of anarchy in our roading systems has been the development of a social attitude that can only be described as "anti-authoritarianism". Any attempt to enforce compliance with the road rules at the seventies level would meet such massive public resistance it would be doomed to failure. This resistance would undoubtedly be lead by the "civil libertarian" movement who fight any attempt to impose social responsibility on individuals.

It is my opinion that the only effective solution is long-term social change. I'm not sure where it has shown up in the postings, but I have already said in another comment that this is a social problem, not just a driving/road safety issue.
Brian