Effects of implementation intentions on the self-reported frequency of drivers' compliance with speed limits

This study tested the efficacy of implementation intentions in the context of drivers' speeding behavior. Participants (N = 300) completed self-report measures of goal intention and behavior, and they were randomly assigned to an experimental condition, which required them to specify an implementation intention, or a control condition. One month post-baseline, self-reported compliance with speed limits significantly increased for experimental participants but not for control participants. The effects of specifying an implementation intention on behavior increased with the strength of drivers' goal intentions. Finally, analysis of participants' implementation intentions revealed that specifying more behavioral strategies increased the frequency with which participants reported complying with the speed limit. Implications of the findings are discussed in relation to enhancing road safety interventions.     

Self-reported Attitude Towards Speeding and Its Possible Consequences in Five Different Road Contexts

Driving above the permitted speed limit is a common violation on the roads of Great Britain. Moreover, speeding is associated with negative consequences in the form of damage, injury and fatal road traffic accidents. The aim of this study was to assess, by means of self-report, the prevalence of this social problem across five different contexts: a residential road, a busy shopping street, a dual carriageway, a winding country road, and a motorway. The extent to which speeding was perceived to be associated with negative consequences was also assessed. Results suggest that most drivers make judgements about the type of road on which they are driving and the degree of speeding that is acceptable, and that their intentions to speed vary accordingly. Some drivers reported a consistent intention to speed, however, and these people were characterized by greater general deviance on the road (e.g. high violation score), rather than by a stronger tendency to underestimate the negative consequences. In general, however, younger people and those with less regard for negative consequences reported stronger intentions to speed. These results are discussed with reference to strategies for addressing the problem of speeding. © 1997 John Wiley & Sons, Ltd.     

The development, validation, and application of a video-based technique for measuring an everyday risk-taking behavior: drivers' speed choice

Drivers' choice of speed is an important aspect of everyday risk-taking behavior because it has been shown to be one of the most important predictors of road accident involvement. This research developed, validated, and applied a measure of drivers' speed choice that combined a high degree of experimental control with external and ecological validity. In Study 1, a video-simulation measure of drivers' speed choice was developed and found to relate specifically to speed-related accident involvement, implying a degree of external validity. In Study 2, the measure was used to investigate the effect of auditory feedback on drivers' speed choice. It was found that increasing the level of internal car noise decreased drivers' preferred speeds. Further analyses indicated that this was likely due to perceptual effects on speed estimation. Results are discussed in terms of road safety and the ability of video-based measures to facilitate experimental control over tasks involving complex ecological stimuli.     

An empirical analysis of driver perceptions of the relationship between speed limits and safety

In recent decades, it has become more common for speed limits to be set for political reasons rather than for safety reasons. As a consequence, the motoring public seems to have increasingly begun questioning the rationality of speed limits. This is evident in observed speed data that show that the majority of drivers routinely exceed posted speed limits. A key motivating factor in drivers’ tendency to exceed the speed limit is that they believe that the excess speed does not threaten safety. This paper, specifically studies this matter by using a survey that asked drivers how fast above the speed limit they feel they can drive before safety is threatened. A probabilistic model is estimated using data gathered from 988 drivers in Indiana. Estimation findings show that drivers’ perception of the speed above the speed limit at which they will receive a speeding ticket is a critical determinant of what they believe is a safe speed – suggesting that enforcement plays an important role in safety perceptions. Other variables found to be significant factors in determining the speed above the speed limit at which safety is first threatened include age, gender, being previously stopped for speeding, and drivers’ ethnicity.     

Do drivers differ in their attitudes on speed limit compliance between work and private settings? Results from a group of Nigerian drivers

Existing evidence suggests that drivers, particularly those who work in companies with strong road safety cultures exhibit different sets of speeding attitudes and behaviours in work and private driving. Using Ajzen and Fishbein’s (1980) Theory of Planned behaviour (TPB) and on-road driving experiments, this study examined the self-reported and objective behaviour of driving within posted speed limits for a sample of fleet drivers. The findings show that the TPB explained up to 24% of the variance in intention to comply with speed limits. Drivers’ attitude emerged as the most significant predictor and strongest correlate with intentions to comply with the speed limit in both work and private vehicle.Further analysis revealed participants had a higher intention to comply with speed limits in their work than private vehicle. Also, investigation of the relationship between TPB variables and observed speeding behaviour suggests that participants with higher intention to comply with the speed limit or high perceived behavioural control (PBC), exceeded the speed limit less often than those with lower intention to comply with the speed limit or low PBC. The findings have important theoretical and applied implications for development of better speed limit compliance interventions to improve driving behaviour, and road safety in general.     

A naturalistic study of the impact of message framing on highway speeding

Speeding is the most common road violation, and is one of the main causes of crashes. To protect road users, authorities use sanctions and preventive measures to prompt drivers to observe speed limits. However, the efficacy of prevention messages varies according to a number of factors, among which risk framing is important. We ran a study to test whether gain is more effective than loss (framing effect). Four anti-speeding messages were presented on variable-message signs, along one side of a busy 8-lane highway in France (speed limit: 130 km/h – 80 mph), during 6 weekends. Within a between subject design, the messages differed in orientation (gain vs. loss vs. no message) and theme (crash vs. fuel consumption). The drivers’ speed was recorded on the highway 2 km (1.25 miles) after the sign (6486 recordings of speed). The results showed that speed was lower when a message was displayed than in the control condition, and when the message was gain-framed rather than loss-framed. These effects were stronger on the left lanes (overtaking lanes). Hence, gain framed messages are recommended for prevention campaigns at least when no risk factor is salient.     

Examining U.S. drivers’ characteristics in relation to how frequently they engage in speeding on freeways

Speeding and speed-related crashes have consistently represented over 25% of all traffic fatalities over the past two decades. The severity of these speed-related incidents not only impact the drivers but all road users. Thus, characterizing drivers who speed, understanding their motivations, and identifying the types of risky driving behaviors associated with speeding play a critical role in developing, implementing, and sustaining effective countermeasures. Using a survey administered to a U.S. nationally representative sample (N = 2,930 licensed drivers aged 16 or older), this study develops a partial proportional odds model to examine differences in characteristics between types of speeders – frequent, occasional, and non-speeders – and explores characteristics and risk driving behaviors that are most associated with speeding behavior. Additionally, motivations for speeding are examined for drivers who frequently speed compared with those who occasionally speed. Results show speeders tended to engage in other unsafe driving behaviors, such as distracted, aggressive, unbelted, and alcohol-impaired driving. Among demographic and socio-economic variables examined in this study, drivers’ age was the greatest associated determinant. The association with engagement in red-light running, however, outweighed that with drivers’ age. Interestingly, the interaction between educational attainment and engagement in aggressive driving was also predictive of speeding behavior. For motivations for speeding, frequent speeders were more likely to report enjoying driving fast and disagreeing with speed limits compared with occasional speeders. The findings of this study are useful towards identifying the various characteristics and behaviors of drivers who engage in speeding, which can provide future insights into where effective countermeasures and prevention efforts should be focused.     

Influence of the penalty point system on driving behaviour: drivers' point of view

On July 1, 2006 a penalty point system was introduced in Spain. One year later, a reduction of 14.3% was observed in road traffic casualties, whilst the previous year that figure was 4.9%. A national telephone survey was conducted on a sample of 2.014 respondents to explore the drivers' point of view about the influence of the penalty point system on driving behaviour. Results point to a moderate behavioural change, mainly in relation to speeding and mobile phone misuse, this change being slightly more intense in drivers who were fined during the previous year. Awareness of road traffic accidents increased in around 40% of drivers. Lastly, mobility loss stands out as the most worrying and presumably most influential consequence of driving license loss.     

Application of the theory of planned behaviour to the prediction of objectively assessed breaking of posted speed limits

In two studies the Theory of Planned Behaviour (TPB) including moral norms, anticipated regret and past behaviour was applied to predicting intention to exceed the posted speed limit across different roads and objectively assessed speeding behaviour. All measures except behaviour were taken by self‐report questionnaires referring to different driving scenarios. The behaviour measures were based on performance in a simulator (Study 1) or unobtrusive on‐road speed camera assessment taken without driver awareness (Study 2) across roads with varying posted speed limits. Results are reported averaged across road types in both studies. In Study 1 (N = 83), 82% of the variance in intentions to speed was explained, with attitudes, subjective norms, perceived behavioural control (PBC), moral norms, anticipated regret and past behaviour being significant predictors. A total of 35% of the variance in speed as assessed on a driving simulator was accounted for with intentions, PBC, moral norms and previous accidents being significant predictors. In Study 2 (N = 303), 76% of the variance in intentions to speed was explained with attitudes, moral norms, anticipated regret and past behaviour being significant predictors. A total of 17% of the variance in speed as assessed on‐road was accounted for with intentions and moral norms being significant. Practical implications of the findings for road safety are discussed.     

Effects of reduced contrast on the perception and control of speed when driving

Misperception of speed under low-contrast conditions has been identified as a possible contributor to motor vehicle crashes in fog. To test this hypothesis, we investigated the effects of reduced contrast on drivers' perception and control of speed while driving under real-world conditions. Fourteen participants drove around a 2.85 km closed road course under three visual conditions: clear view and with two levels of reduced contrast created by diffusing filters on the windscreen and side windows. Three dependent measures were obtained, without view of the speedometer, on separate laps around the road course: verbal estimates of speed; adjustment of speed to instructed levels (25 to 70 km h(-1)); and estimation of minimum stopping distance. The results showed that drivers traveled more slowly under low-contrast conditions. Reduced contrast had little or no effect on either verbal judgments of speed or estimates of minimum stopping distance. Speed adjustments were significantly slower under low-contrast than clear conditions, indicating that, contrary to studies of object motion, drivers perceived themselves to be traveling faster under conditions of reduced contrast. Under real-world driving conditions, drivers' ability to perceive and control their speed was not adversely affected by large variations in the contrast of their surroundings. These findings suggest that perceptions of self-motion and object motion involve neural processes that are differentially affected by variations in stimulus contrast as encountered in fog.     

Drivers' compliance with speed limits: an application of the theory of planned behavior

The theory of planned behavior (TPB; I. Ajzen, 1985) was applied to drivers' compliance with speed limits. Questionnaire data were collected for 598 drivers at 2 time points separated by 3 months. TPB variables, demographic information, and self-reported prior behavior were measured at Time 1, and self-reported subsequent behavior was measured at Time 2. In line with the TPB, attitude, subjective norm, and perceived control were positively associated with behavioral intention, and intention and perceived control were positively associated with subsequent behavior. TPB variables mediated the effects of age and gender on behavior. Prior behavior was found to moderate the perceived control-intention and perceived control-subsequent behavior relationships. Practical implications of the findings for road safety and possible avenues for further research are discussed.     

When norms turn perverse: Contextual irrationality vs. rational traffic violations

A perfectly adequate traffic rule can turn “perverse” in situations when it does little to enhance road safety but seems – at least in the drivers’ minds – directed primarily at punishing those who violate it. This study examined traffic rule obedience in situations in which the rule was not in accordance with real safety needs. Six rules with major impact on road safety were analyzed: waiting at red traffic lights, legal overtaking, obeying the 50 km/h speed limit, wearing seatbelts, legal stopping/parking, and driving the car in good technical condition. Participants evaluated how adequate these rules are for safety. Then they were faced with six scenarios, that made each of these rules appear irrational, and were asked to report their potential engagement in deviant behavior. The survey data were collected in a sample of 605 drivers. Multiple regression analyses showed that in most situations rule violation depended on the usual deviant behavior, perceived irrationality of the rule, little respect for the law and low risk perception. These factors best explained the 50 km/h speed limit violation. The results suggest that the lack of situational risk factors, which makes the rule look meaningless, is important determinant of rule violation. Implications for massive disobedience and road safety are discussed.     

Driving speed choice: The role of conscious monitoring and control (reinvestment) when driving

This study aimed to examine the role of reinvestment - the propensity to consciously monitor and control actions (movement specific reinvestment) and to consciously monitor and evaluate decision making processes (Decision specific reinvestment) while driving in everyday risky scenarios. The study also aimed to evaluate the association between reinvestment and previously validated driver attitude measures. Fifty one participants completed a series of questionnaires (Driving Self-Efficacy Scale, Driver Attitude Questionnaire, Movement Specific Reinvestment Scale, Decision Specific Reinvestment Scale) after which they completed a test phase in a driving simulator. In the test phase, driving scenarios included roads with different markings (i.e., double yellow, wide centrelines, wire rope barriers, Audio Tactile Profiled markings) and alerting scenarios (i.e., police car present, high crash risk area sign, reduced speed zone). Results revealed that on risky roads (wide centrelines), participants with a high propensity for decision specific reinvestment drove slower than those with a low propensity. Driver experience, attitudes towards speeding and scores on the Decision Reinvestment subscale of the Decision Specific Reinvestment Scale significantly predicted speed choice. More experienced participants with higher scores on the Decision Reinvestment subscale were more likely to drive slower and participants with worse attitudes towards speeding were likely to drive faster. Participants with a low propensity for movement specific reinvestment (specifically, Movement Self-Consciousness) reduced their speed to a greater extent than those with a high propensity when driving in the police car scenario. There was some evidence to suggest that high decision specific and movement specific reinvesters were more likely to be involved in crashes and receive driving infringements. The current study is the first to demonstrate a significant relationship between reinvestment and driving. The implications of these findings for road safety are discussed.     

The effect of speed limit credibility on drivers' speed choice

Credibility of speed limits is a key factor affecting drivers’ compliance with speed limits. Two experiments were conducted to investigate how credibility of speed limits affects judgments of appropriate speed. The first experiment aimed to establish speeds deemed appropriate by investigating Malaysians drivers’ judgments of the appropriate speed to drive based on photographs of roads with the speed limit sign erased. Drivers chose speeds which correlated with but were higher than the actual speed limits of the roads. Analysis of road characteristics suggested they based their decisions mainly on features of the road itself rather than of the roadside. The second experiment tested the impact of credibility of speed limit information on the speed drivers judged appropriate. Drivers judged the appropriate speed to drive for the same photographs as in Experiment 1 with speed limit information provided. Four conditions were included: two conditions where the speed limit posted was 10% higher or 10% lower than the appropriate speed established in Experiment 1 (credible speed limits), and two conditions where the posted speed limit was 50% higher or 50% lower than the appropriate speed (non-credible speed limits). Posted speed limits did affect drivers’ judgments about the appropriate speed to drive. Credibility also influenced judgments whereby drivers selected appropriate speeds consistent with the speed limits for the 10% lower condition, but not for speed limits that deviated highly from the appropriate speed judged in Experiment 1.     

Spanish young adults' perceptions of the costs and benefits of risky driving behaviors

We used an open-ended survey to elicit Spanish young adults' perceptions of the benefits and drawbacks of speeding and not wearing a seatbelt (or helmet). Around half of the sample reported past engagement in these two risky behaviors, although forecasted engagement was low. Past and forecasted risk taking were positively correlated. Participants provided more drawbacks than benefits of each risky behavior. Drawbacks typically referred to a combination of behavioral acts and social reactions (e.g., accident, punishment) that occurred during the journey. By contrast, benefits largely referred to personal effects (e.g., save time, comfort) that occurred after the journey had ended (speeding) or during the journey (not wearing a seatbelt/helmet). These findings contribute to our theoretical understanding of young adults' risk taking on the road, and to the development of road safety programs.     

A replication of the use of public posting in traffic speed control

In an attempt to replicate several previous studies, a reversal design was used to assess the effects of publicly posted feedback on vehicle speed reduction. The intervention phases consisted of daily posted feedback that supplied drivers with either accurate or inaccurate information regarding the percentage of vehicles exceeding the speed limit on the road. Results from the two feedback conditions indicated no speed reduction in comparison to baseline levels. These results are discussed in light of previous studies that found strong effects for such feedback. Baseline levels of driver compliance and methodological differences may limit the effectiveness of posted feedback in reducing speeding.     

Implementation of automatic speed enforcement: Covariation with young drivers’ reported speeding behaviour and motivations

IntroductionSpeeding represents one of the main causes of road crashes worldwide, particularly among young drivers who are over-represented in road-crash statistics. For promoting road safety in France, an automatic speed enforcement (ASE) system was introduced late 2002.ObjectiveIn order to examine its efficiency on speeding and its motivations, we compared young drivers’ intentions and beliefs about speeding between the introduction of ASE (T1) and its completion in 2005 (T2) via a large survey based on the extended Theory of Planned Behaviour (TPB). We assumed the introduction of the ASE would covariate with a reduction in intention to speeding between T1 and T2 and a change in the extended TPB factors according to gender and driving experience.MethodOne thousand one hundred and ninety-two young participants (49.7% men) divided into novice, beginner, and more-experienced drivers filled in a questionnaire based on the extended TPB about their driving behaviour and history at T1 and 24 months later (T2).ResultsMen, beginner and more-experienced drivers expressed more intention to speeding within the next 12 months at T1 and showed a higher decrease in intention between T1 and T2 as compared to women and novice drivers. The extended TPB accounted for 59% of the variance in the decrease of the intention to speeding. Its main predictors were: lower perceived behavioural control over speeding, less social pressure, lower perceived similarity with the prototypical deviant driver, and higher comparative optimism. Secondly, slightly more positive behavioural beliefs and more negative outcome evaluations predicted this decrease.ConclusionPractical implications of the findings for road safety are discussed.     

Beyond cognition: predicting health risk behaviors from instrumental and affective beliefs.

OBJECTIVE: Two studies assessed the relative contribution of affective and instrumental beliefs to the prediction of 2 risk behaviors: driving above the speed limit and smoking. DESIGN: Both studies took the form of large-scale questionnaire surveys (Study 1, N=292; Study 2, N=500) measuring instrumental and affective beliefs and self-reported behavior. In both cases, behavior was also measured objectively. OUTCOME MEASURES: In Study 1, speeding behavior was measured via infrared camera along sections of road with 30 mph, 40 mph, and 60 mph speed limits. Self-reports of speeding in these same contexts represented a 2nd dependent variable. In Study 2, level of smoking was measured via a carbon monoxide monitor, and participants were asked to indicate the number of cigarettes they smoked in a week. RESULTS: In Study 1, positive and negative instrumental and affective beliefs were significant predictors of self-reported speed. The most powerful predictor was negative affective beliefs. Observed speed was predicted by negative affective beliefs only. In Study 2, the significant predictors of self-reported smoking and objective measures of smoking were positive and negative affective beliefs. CONCLUSION: The findings indicate the importance of affective beliefs across 2 health risk behaviors. Implications for social cognition models and interventions are discussed.     

How fast would you (or should you) drive here? Investigation of relationships between official speed limit,perceived speed limit,and preferred speed

Speed is a critical risk factor, which makes its management the central point of the Vision Zero approach. Driving speed is influenced by speed choice, and in turn by the perception of the road parameters, as well as by the characteristics of drivers. Credible speed limits and self-explaining roads have been suggested as promising countermeasures; however, these rather theoretical concepts have only rarely been operationalized and quantified.The aim of this study was to investigate the relationships between speed indicators (official speed limit, perceived speed limit, preferred speed), as well as their differences, and to determine which road and personality characteristics influence them. Compared to previous studies, we introduced several innovative features, including a richer personality dataset based on three different questionnaires, a focus on all three types of roads (urban, rural, transition), and representative data on observed speeds.Using statistical models of the speed indicators, we found that both speed limit belief and speed choice, as well as their differences, are often influenced by the same characteristics. These are mainly more generous road design (higher road class, higher speed limit, and wider road) and the presence of additional elements (vegetation, pavements, and pedestrian crossings). These characteristics may help improve the credibility of speed limits and self-explaining performance.