One of the most difficult aspects of dealing with any subject, especially one such as dangerous driving practices, is a failure to provide a common base for discussion. This problem continues to plague aggressive driving. Until we reach some agreement as to the meaning of "aggressive driving," development of solutions is neither going to be practical nor measurable. An effort to develop that definition currently is underway under an NCHRP grant. In fact, next week, a panel of experts from various fields of traffic safety will be meeting in Washington, DC. One of their tasks is to reach a common understanding. Clearly stated definitions of aggressive driving made available before that meeting will be of value.

The following is a distinction we have made in our research. We have found that the three concepts are distinct and involve unique predictors in both hypothetical and actual (open road) driving situations.

Mild Driver Aggression:

Includes any behavior intended to harm another in the driving environment.
Can include physical, emotional, or psychological harm.
"Mild" refers to the limited severity of their actions.
They can escalate to more frequent and more severe acts of aggression.
Common compared to driver violence (see below).
Equally common among men and women drivers.
e.g. horn honking, yelling, swearing, hand gestures, purposeful tailgating

Driver Violence:

More extreme form of aggression.
Intent is to harm, but also an element of power, control, and satisfaction in the harm of others.
More severe action and outcome than mild aggression.
Road rage reports often talk about the violent manifestations of the "rage" (rage is an emotion that is neither sufficient nor necessary for mild aggression or violence)
Less common than mild aggression.
More common among men than women (partly due to the physical nature of the aggression)
e.g. fights, shootings, vandalism, throwing objects

Assertive Driving:

Fox network notion of "aggressive" driving.
e.g. speeding, weaving through traffic, running lights
Dangerous, illegal etc. but they are not intended to harm.
Predominantly time urgent, impulsive, self relevant actions.
Unfortunately, too many reports include a confound of these with true aggression so they overestimate the link between aggression and collisions or violations.

To define aggressive driving we should first step back a little to the definition of aggression, to attack.

Aggressive driving is therefore a condition where the driver is making an "attack" on another road user either overtly or subconciously.

The speeder is not driving aggressively by the act of speeding. Only when they follow too closely to force their way through or weave from lane to lane without regard for the others about them does it become aggressive.

The driver who proceeds down the passing lane at the speed limit when the other lanes are free is aggressive.

Similarly the rolling stop at an intersection with a clear view and no other traffic isn't aggressive. Illegal maybe.

Any form of driving which attempts to impress your will on another road user is aggressive. Ignoring the pedestrian at a crosswalk because the road is empty behind you(they can cross after you pass), is aggressive. The pedestrian who steps into the road without looking, at an intersection because they have right of way, is aggressive.

Laws regarding road use are a generalization for the benefit of the road users but disregarding the law, or for that matter observing the law, is not in itself an aggressive behaviour.

Aggression is a state of mind that can be taught or acquired and if it is recognized can be controlled by either the aggressor or authority. Similarly consideration for other road users can also be taught or acquired.

It is the responsibility of us all to try and provide a good example to others by our own behaviour and by training from the earliest opportunity.

I aggree with Trevor that disregarding the law is not necessarily aggressive. It's just not possible to obey the law to the letter all the time. For one thing we've all got to get along, as Rodney King said, and not everyone knows the letter of the law.

That is not to say we can break the law any time we want, but as long as we're not causing problems and driving reasonably, we're not being aggressive drivers and we're not being unsafe. Drivers who drive by the book may be considered aggressive if they cause problems by ignoring what's going on around them and doing their own thing.

That includes the drivers who stick in the middle lane and won't move over to let a truck pass. They're obeying the law but they can make things very difficult for truck drivers who find it more difficult to pass by going into the fast lane.

By: Richard I. Wark and Richard A. Raub
Northwestern University Center for Public Safety
Emphasis Area Manager and Researchers
Aggressive Driving Emphasis Area, NCHRP 18-18(3), Implementing AASHTO Strategies

The purpose of a workshop held November 16th and 17th at the National Research Council headquarters in Washington D.C. was to design strategies to address aggressive driving. This workshop was one of several as part of a National Cooperative Highway Research Program (NCHRP) project addressing different problems with the road and drivers, each aimed at a different problem area with the overall goal of reducing fatalities. Practitioners and researchers discussed current efforts aimed at aggressive driving as operated in a number of states, and delineated aspects leading to success. A number of issues concerning the definition of aggressive driving as well as approaches to combating it were considered. While consensus certainly was not achieved, the discussion was quite valuable in clarifying the relevant questions and issues. Among these were:

* Is a definition needed in order to operate an effective program or is it sufficient to note the specific targeted driving behaviors (violations)? Many of those present believed that a definition is necessary to have common measures of program effectiveness. Moreover, a definition probably can accommodate both violations and behaviors identified as being aggressive.
* Can aggressive driving occur in the absence of another vehicle or pedestrians? Here, most suggested definitions reviewed to date suggest that aggressive driving is occurring when others are affected.
* Will conceptions of aggressive driving differ between different locations and cultures?
* Do successful programs require a specific aggressive driving statute or can existing traffic law be effectively used? With a few exceptions, the current aggressive driving statutes attempt to represent a middle ground between charging a driver with multiple violations and charging reckless driving.
* Is the frequency of aggressive driving increasing or just the awareness? This question points to the need for a definition in order to bring about consistency in measuring the how frequently aggressive driving occurs
* What is the relationship between aggressive driving and environmental conditions such as congestion, signal timing, appropriate speed limits, and other traffic engineering related elements? Research presented from Israel suggests that drivers are more likely to drive aggressively around traffic signals when they are not timed properly.
* What is the relative efficacy of enforcement, education, public information, and engineering approaches in combating aggressive driving and how can they be most effectively combined? In general, attendees agreed that long-term enforcement may not be an effective use of police resources, especially if other approaches will help alleviate the problems.

In order to help clarify the definitional issues as well as examine the possibility of employing an empirical approach to definition and program planning, participants in both the aggressive driving as well as the other workshops completed the survey appearing below. As you can see, the items are listed in descending order of their likelihood of being viewed as aggressive. While there appears to be some tendency to view actions that violate norms of fairness and are directed toward other drivers as being aggressive, the results are not totally clear.

We would be very interested in feedback concerning the issues raised at the workshop as well as your take on the questionnaire results.

(PS. Sorry for the formatting, but there is not enough width to show the questions with their answers to the side. They are underneath each question).


Responses to the Aggressive Driving Survey
NCHRP 17-18(3) Workshops
Washington D.C., November 2000
Yes
Question Freq. Pct
9. Traffic congested and very slow. Driver A 42 93.3%
pulls onto the shoulder and advances many car
lengths before returning to the traffic stream.
15. A driver signals to move to the left lane. 42 93.3%
Driver A in that lane speeds up to prevent the lane
change.
8. Same scenario as #7 above, except the original 38 84.4%
driver accelerates to the prevailing speed.
Driver A, who is following, continues to flash
lights.
12. Driver A seeing the traffic signal turning red 38 84.4%
speeds up but still enters the intersection after
the light turns red.
13. Driver A has had to stop for two traffic signals 35 77.8%
in succession because they turned red just
prior to approach. Driver speeds up and enters
the third intersection just after the signal turns red.
21. At a busy intersection, a driver turning left 34 75.6%
waits for pedestrians to cross. Driver A in
following vehicle blows his horn.
22. Driver A cannot complete a left turn on the 34 75.6%
protected left-turn arrow because pedestrians
are crossing against the "no walk" sign. He
blows his horn and shouts at the pedestrians.
16. Same scenario as #15, but Driver A signals and 33 73.3%
then forces his way into the lane causing the
other driver to slow abruptly.
2. Traffic very heavy; speeds are less than 45 31 68.9%
mph. Driver A changes lanes frequently,
generally moving faster than the other traffic.
1. Traffic relatively heavy; drivers traveling at or 29 64.4%
above the limit. Driver A goes faster than
speed limit and changes lanes frequently.
24. The same scenario as #23. Driver A pulls into 28 62.2%
the merge lane and travels at the speed of the
queue to prevent other drivers from passing.
23. In a construction zone, two lanes merging into 27 60.0%
one. Traffic in the through lane is moving
slowly; the other lane is open to the merge.
Driver A proceeds to the merge passing the
slow traffic.
14. Driver A has waited five minutes to make a 26 57.8%
left-turn which only can be done on the green
arrow. He makes the left turn on the third try,
but only after green arrow has turned to red.
17. Driver A is on cell phone and does not notice 26 57.8%
light turn to green. Driver in following vehicle
blows his horn and Driver A gives the finger salute.
25. A driver has an important meeting and is 26 57.8%
traveling faster than the traffic because he was
delayed significantly by a flat tire.
11. Traffic congested at the on-ramp. Driver A 23 51.1%
from entering from ramp crosses solid white line
to enter mainline stream early.
18. Driver A slows but does not stop for 4-way 23 51.1%
stop signs. None of the signs conform to the
national standards for posting such signs.
4. Traffic is light, mostly in the outside lanes. 19 42.2%
Driver A is traveling at least 75 mph in the
inside lane.
6. Same scenario as #5, except Driver A is 19 42.2%
following vehicle. Driver A flashes lights
several times, then passes on right.
10. Same scenario as #9, but Driver A pulls onto 19 42.2%
the shoulder several car lengths before the exit
and exits.
7. Same scenario as #6, but traffic heavy. Driver 18 40.0%
A cannot return to original lane, but also does
not match prevailing speed. Driver in following
vehicle flashes lights several times.
19. At the intersection, left turns can be made only 14 31.1%
on the left arrow. Cars in the through lane
block entrance to the left turn lane. Driver A
enters the painted median to reach the left-turn lane.
5. Traffic moderate. Driver A pulls into the inside 13 28.9%
lane to pass at less than the prevailing speed.
He does not return to his original travel lane.
Driver behind flashes lights several times;
passes on right.
3. Traffic moderate, many drivers moving above 11 24.4%
the limit. Driver A is traveling at 70 mph;
signals and changes lanes frequently; does not
appear to interfere with other drivers.
20. At a congested intersection, Driver A enters 8 17.8%
the intersection on the green light, but cannot
clear it. Drivers entering from the cross street
cannot move.


Number of Responses 45

I want to thank Richard Wark and Richard Raub for their excellent summary of the NRC workshop. The importance of a definition of aggressive driving for the development of valid and reliable measures of the related behaviours seems to have been underscored in your discussions. A number of important questions were raised to which we do not yet have answers. The most interesting concerns the general agreement among workshop participants that where aggressive driving behaviour is concerned, long-term enforcement may not be an effective use of police resources. This implies that there are other long-term measures which may be more effective. What was the view regarding the potential long-term effect of social marketing/public education campaigns? I would also be interested in knowing whether participants discussed the possibility of some systematic field studies to measure the actual incidence of specific behaviours associated with aggressive driving.

Hello,
I am studying aggressive driving and have just come upon the conference hosted at this site. I thought it might be a good idea to generate a list of potential grant sources for those studying this phenomena, as I know I could use additional money to conduct my research. I have checked out many traditional government sources (U.S.), but I was hoping to get more information on the private sector. Perhaps a page could be dedicated to the collection and dissemination of this type of information. My research is in the United States, but there may be sources in other nations that researchers in those countries may benefit from hearing about. There may also be international sources of which I am not aware. I found several insurance companies who may fund aggressive driving research and I would be happy to provide links and/or addresses if others also think this is a good idea.
Sincerely,
Chris Dula (cdula@vt.edu)
Research Associate
Center for Applied Behavior Systems
Virginia Tech