Road safety/Overestimation of skill

There are many sources which lead to the conclusion that drivers routinely overestimate their own skill, and none of which I am aware that show anything different. This is consistent with the psychological concept of illusory superiority or superiority bias.

What is dangerous driving? I have a tendency to believe that everyone's driving is dangerous, except my own

George Bernard Shaw.

  • A survey of British motorists[1] found that:
    • 40% rated the overall standard of driving as bad but only 2% rated their own driving as bad
    • 24% rated the overall standard of driving as good, but 75% rated their own standard as good
  • An attempt to research ways of correcting drivers' overestimate of their skills failed due to the unwillingness of drivers to accept even the most obvious driving errors.[2]
  • A survey of motorway drivers[3] found that:
    • on a scale of 1 (poor) to 5 (good), they rated themselves as an average 3.9 with other drivers being rated as 2.7.
    • 39% admitted having "nodded off" on the motorway
    • one third underestimated safe stopping distances.
  • Up to 80% of drivers surveyed rate themselves "above average" on a number of important characteristics.[4]
  • Study subjects were asked about their competence as drivers in relation to a group of drivers. The results showed that a majority of subjects regarded themselves as more skillful and less risky than the average driver in each group respectively.[5]

I have some more sources on order, but everything I can find essentially says the same thing: most drivers consider themselves to be better than most other drivers, to an extent that is not consistent with any plausible non-normal distribution of skill (if such could be proposed without violating Occam's razor). Whether this is due to their overestimation of their own skill, their falsely low perception of the skill of others, or a bit of both, is not always clear, but the Dunning-Kruger hypothesis indicates a bit of both.

Further reading

In this study subjects were asked about their competence as drivers in relation to a group of drivers. The results showed that a majority of subjects regarded themselves as more skillful and less risky than the average driver in each group respectively. This result was compared with similar recent findings in other fields. Finally, the consequences for planning and risk taking of seeing oneself as more competent than others were discussed briefly.
While it is known that drivers as a group rate their skills as better than the average, the mechanism underlying this illusion is unclear. It is possible, for example, that it is due either to a “positive-self” or “negative-other” bias. A test of these alternative hypotheses revealed that judgments are consistent with a “positive-self” bias. An attempt was made to determine whether the illusion was present in all areas of driving skill or whether there were specific components where the illusion was absent. For men, the bias was present in all the driving components examined. For women, there were several areas where they rated themselves less positively than the men, and four areas where they showed no evidence of any bias. When the effects of driving experience were statistically controlled for, however, these sex differences were found to be substantially reduced.
Research into self-evaluation of driving abilities has shown that drivers in North America and Europe consider that their driving abilities to be superior to those of the average driver. This survey (N = 454), carried out using a questionnaire, has confirmed this phenomenon in France where about 60% of the subjects rated themselves superior to other drivers in general. [...] This interpretation would thus confirm the hypothesis that all subjects, whether they consider themselves superior or not to other drivers in general, believe they commit fewer offences than other drivers in general.
This national survey was designed to identify factors that motivate safe driving behaviors and to determine how people rate the safety of their driving. It was found that drivers tended to rate themselves above average in terms of being safe drivers. Negative consequences such as the potential for a car crash and increase in car insurance were cited as important factors in increasing concern for safe driving. It was concluded that increased enforcement and awareness of negative outcomes may be effective in promoting safe driving practices.
Australian (N = 201) and Finnish (N = 203) drivers completed Type-A and Sense of Coherence questionnaires, Driver Behaviour Inventory, Driver Social Desirability Scale, self-reported number of accidents, penalties and driving speed and the Driver Skill Inventory (DSI), which measures driver's self-assessment of his/her perceptual-motor and safety skills. The English version of the DSI had the same factor structure and reliability as the original Finnish version and is, therefore, a viable instrument for measuring drivers' self-assessment of their perceptual-motor and safety skills in English-speaking countries. Hierarchical regression analyses showed that the number of accidents and penalties as well as the self-reported driving speed were predicted by safety skills whereas perceptual-motor skills predicted the number of penalties. Perceptual-motor skills were positively related to life-time mileage, being male, driving aggression and alertness, and sense of coherence, but negatively to dislike of driving and age. Safety skills were predicted by impression management, nationality, driving aggression and alertness. Results suggest that drivers with strong trust of their perceptual-motor skills have an emotional attitude to driving and overestimate their driving abilities, but drivers emphasising safety skills have a matter-of-fact attitude to driving.
This study investigates the self-enhancement bias in driver attitudes, the finding that drivers rate themselves better than the average driver on safety and skill perceptions (Svenson, 1978 and Svenson, 1981; McCormick et al., 1986). A sample of 86 New Zealand drivers were asked their perceptions of their own and others' speeds in two conditions, 50 km/h and 100 km/h. The results established the self-enhancement bias for speed and safety, but not skill. Between 85% and 90% of drivers claimed to drive slower than the ‘average driver.' A new methodological technique derived from Harré and Gillett (1994) was used to investigate the direction of the self-enhancement bias. The results support the Downward Comparison Theory (Wills, 1981) because drivers consider other drivers negatively, rather than exaggerating their self-perceptions.
One hundred and thirteen drivers were surveyed for their perceptions of driving speed to compare self-reported average speed, perceived average-other speed and the actual average speed, in two conditions (50 and 100 kph zones). These contrasts were used to evaluate whether public safety messages concerning speeding effectively reach their target audience. Evidence is presented supporting the hypothesis that drivers who have a biased perception of their own speed relative to others are more likely to ignore advertising campaigns encouraging people not to speed. A method of self-other-actual comparisons detects biased perceptions when the standard method of self-other comparison does not. In particular, drivers exaggerate the perceived speed of others and this fact is masked using traditional methods. The method of manipulation is proposed as a way to evaluate the effect of fu[ture advertising campaigns, and a strategy for such campaigns is proposed based on the results of the self-other comparisons.
Previous research has found that drivers tend to consider themselves superior to their peers on both driving ability and driving caution, as well as judging themselves as at less risk of a crash (crash-risk optimism). These studies have relied on explicit measures by getting drivers to respond to written items. The current study measured 158 New Zealand drivers’ explicit and implicit attitudes towards their own driving attributes in comparison with others. Implicit attitudes were measured using a computer-based reaction time task, the Implicit Association Test (IAT). Both explicit and implicit self-enhancement biases were found in driver ability and driver caution. Implicit biases were considerably stronger than explicit biases and men demonstrated stronger self-enhancement biases in driving ability than women. Explicit and implicit ratings of driving ability and explicit ratings of driver caution predicted crash-risk optimism. Explicit and implicit ratings of driving caution predicted a measure of driving violations. The implications for safety interventions and research on drivers’ mental processes are discussed particularly in regard to the ability of implicit measures to bypass social desirability effects.
This study examines risk comparative judgments and risky behaviors while driving a car among competitive road cyclists (n = 119) and among controls (i.e., drivers who have almost no cycling experience, n = 142). A questionnaire-based cross-sectional survey was conducted. Results showed that competitive road cyclists assess their own vulnerability to be involved in an accident while riding (VAR) as being lower than that of the average cyclists, and their abilities to manage risks while riding (AMRR) as being higher. They assessed their own vulnerability to be involved in an accident while driving a car (VAD) as being lower than that of the average drivers, and their own quality of reflexes while driving a car (QRD) as being higher. Their tendency to express comparative optimism while assessing their comparative VAD and QRD was higher than that of controls. They also reported more prudent behaviors while driving a car than did controls. Results are discussed, as well as implications in terms of prevention.
Evaluating motorists through self-assessment has attracted much interest in recent literature, which is mainly due to the profound impact various parameters of self-assessment can have on the way motorists deal with hazardous traffic situations. Much of the previous work in this area has been hampered both by the lack of adequate sample sizes and, because of the small samples, the evaluation methodologies used. Method: This paper extends previous research in two significant directions: (a) it uses the SARTRE 2 database, which provides more than 17,000 questionnaires from most European countries; and (b) it employs the ordered probit modeling approach, which recognizes the latent nature of self-assessment and explicitly links its dimensions to a set of relevant explanatory variables such as age, gender, region, and income. Results: The results indicate that drivers who rate themselves as both more dangerous and faster than others are, generally, younger men, with higher incomes, break the speed limit more frequently, avoid wearing seat belts, and have been involved in more accidents in the past than other drivers. Interestingly, more experienced and more highly educated drivers assess their driving as less dangerous, but admit to driving faster than other drivers. Impact on Industry: The methodology used and the results obtained can be a significant help in identifying drivers with high and low self-assessment ratings, which can be useful in planning and implementing road safety information campaigns.


  1. Lex report on motoring, Lex Group, 1989
  2. Davis, Death on the Streets, ch.2 ref. 18
  3. Gallup, for General Accident, June 1989
  4. Comparative perceptions of driver ability— A confirmation and expansion, Iain A. McCormick, Frank H. Walkey and Dianne E. Green, Accident Analysis & Prevention Volume 18, Issue 3, June 1986, Pages 205-208
  5. Svenson, O. (1981). Are we all less risky and more skillful than our fellow drivers? Acta Psychologica, 47, 143-148.