The development and validation of video-based measures of drivers' following distance and gap acceptance behaviours

Negative mood mind wandering and unsafe driving in young male drivers

OBJECTIVE

Road traffic crash fatalities disproportionately affect young male drivers. Driver distraction is a leading contributor to crashes. Mind wandering (MW) is a prevalent form of driver distraction that is linked to certain unsafe driving behaviours that are associated with increased crash risk (e.g., faster driving). Negative mood can lead to MW, and thus may represent a causal pathway to MW-related unsafe driving. This preliminary pre-post (T1, T2), randomized, controlled, single-blinded experiment tested whether negative mood, compared to neutral mood, increases MW while driving as well as unsafe driving and emotional arousal during MW. It also tested the moderating contribution of trait rumination and inhibitory control to this proposed causal pathway.

METHODS

Forty healthy male drivers aged 20 to 24 were randomly allocated to a negative or neutral mood manipulation involving deception. Individual differences in trait rumination and inhibitory control were measured at T1. At T1 and T2, participants drove in a driving simulator measuring driving speed, headway distance, steering behaviour, and overtaking. Heart rate and thought probes during simulation measured emotional arousal and MW, respectively.

RESULTS

Negative mood exposure led to more MW while driving (Odds Ratio = 1.79, p = .022). Trait rumination positively moderated the relationship between negative mood and MW (Odds Ratio = 2.11, p = .002). Negative versus neutral mood exposure led to increases in headway variability (Cohen's d = 1.46, p = .026) and steering reversals (Rate Ratio = 1.33, p = .032) during MW relative to focused driving. Between-group differences in emotional arousal were not significant.

CONCLUSION

Results support a causal pathway from negative mood to unsafe driving via MW, including the moderating contribution of trait rumination. If replicated, these preliminary findings may inform the development of interventions targeting this potential crash-risk pathway in vulnerable young driver subgroups.

Analysis of rear-end crash potential and driver contributing factors based on car-following driving simulation

OBJECTIVE

The purpose of the study was to investigate the factors associating the car-following behavior, which could lead to rear-end crash potential. The safe distance in this study was when the traffic flow was in an asymptotic stability state.

METHOD

Traffic flow observation was conducted to observe how vehicle characteristics associating car-following behavior. However, it was not possible to determine the driver characteristics and their driving habits using the traffic flow observation alone. Therefore, a driving simulation and questionnaires were used in combination to investigate how driving characteristics were associate with car-following behavior.

RESULT

From the two observation methods, several factors were found to significantly associate the rear-end crash potential including vehicle types, traveling lanes, the purposes of vehicle usage, age, income, the number of driving hours per week, stress, and anger or aggressive behavior.

CONCLUSION

The traffic flow observation indicated that among the different types of vehicles, sedan/hatchback cars were more likely to be involved in rear-end crashes than others type of vehicles. Vehicles using the high-speed lane typically drove closer to each other and had a higher chance of rear-end collisions. The observation of driver characteristics showed that younger and high-income drivers were more likely to drive with less gap, resulting in higher possibilities of a rear-accident. Despite being in a normal emotional state, drivers with high frequency of stress, anger or aggression while driving had shorter headway distances and were more likely to cause rear-end collisions.

Learner drivers (and their parent-supervisors) benefit from an online hazard perception course incorporating evidence-based training strategies and extensive crash footage

We previously found that a six-session online hazard perception training course, which incorporates evidence-based learning strategies and footage of over a hundred real crashes, improved hazard perception skill and reduced risk-taking intentions in novice drivers who had passed their on-road driving test within the previous three years. However, one issue with targeting crash-prevention training at individuals who are already driving unsupervised is that drivers are at their highest crash risk immediately after they pass their on-road driving test. That is, the training may arrive too late to protect drivers while they are at their most vulnerable. It is also possible that it may prove difficult to persuade drivers to complete an unsupervised training course if they are already licensed to drive independently. Given that learner drivers cannot drive unsupervised, and that they are typically supervised by a parent, one potential strategy is to target the training at learners and to ask their parents to provide one-on-one mentoring throughout the course. We therefore recruited learner driver/parent-supervisor dyads to participate in a randomized control study, with the objective of examining the effects of the hazard perception training course on aspects of driving behaviour associated with crash risk (as measured using validated computer-based tests). Outcome measures included two hazard perception skill assessments (a response time hazard perception test and a verbal response hazard prediction test), and three tests assessing aspects of risk-taking propensity in driving (speed choice, following distance, and gap acceptance). Learners who completed the course (N = 26) significantly improved their scores on both hazard perception skill measures, and also chose safer following distances, compared with a waitlist control group (N = 23). However, the training did not significantly reduce learners' speed choice or gap acceptance propensity. The hazard perception skill of parent-supervisors, who observed the course but did not complete it, also improved on both hazard perception measures, relative to controls. Additionally, both learners and their parent-supervisors reported a range of positive effects on the learners' real-world driving performance. These results suggest that this type of hazard perception training could be beneficial if deployed during the learner phase of driver licensing.

Risky Decision-Making and Hazard Prediction are Negatively Related and Could Be Assessed Independently Using Driving Footage

Introduction

Traffic collisions are a principal cause of death in Europe, disproportionately affecting young drivers. Driving safety depends not only on our ability to anticipate and respond to dangers on the road but also on the level of risk we are willing to engage within our own driving behaviour.

Methods

Hazard prediction (HPr) and risky decision-making (RDM) tests were given to three groups of young Spaniards (169 participants): 54 non-drivers (M=20), 65 novice (M=21) and, 50 experienced drivers (M=26 years old). Both tests presented participants with video clips of driving recorded from the driver’s perspective. The HPr test contained hazardous situations caused by the actions of another road user (eg, a pedestrian crossing the road). Each HPr clip was occluded as a hazard began to unfold and participants were asked to predict “what happens next?” They selected their answer from four on-screen options. The RDM test used clips where any imminent danger would be provoked by the film-car driver’s risky behaviour (eg, overtaking illegally). Participants were asked to report the probability of following certain types of risky behaviour (eg, “Would you go forward with the lights on amber?” or “Would you overtake the cyclist/lorry/bus at this point?”). In addition, the effect of the locality of the driving scenarios was manipulated: they could take place in the participant’s native country (Spain) or in a different country (UK).

Results

Non-drivers and novice drivers were less able to predict upcoming hazards and more likely to make risky decisions. Driving scenarios from another country (UK) provoked riskier decisions than those from the participants’ home country (Spain).

Conclusion

Improvement in HPr skills among novice or new drivers poses a huge challenge as far as driver training is concerned, though it is only part of the solution. Young inexperienced drivers’ willingness to engage in risky behaviour also needs to be tackled. Our results suggest that such RDM can be assessed in a similar way to HPr skill, using a naturalistic approach, which raises the possibility of assessing and training drivers on a wider range of safety-related behaviours.

A thousand years of crash experience in three hours: An online hazard perception training course for drivers

A key goal of driver training is to teach drivers to avoid crashes. However, in traditional driver training, drivers are unlikely to see even a single example of the class of event that we want them to learn to avoid. We developed a six-session automated online hazard perception training course for drivers, which incorporates a range of evidence-based strategies and employs extensive video footage of real crashes. We evaluated this course in a randomized control trial by examining its effects on previously-validated computer-based measures of hazard perception, hazard prediction, speed choice, following distance, and gap acceptance propensity, as well as self-rated measures of driver skill, safety, and real world transfer. We found that the course resulted in significant improvements in hazard perception response time and hazard prediction scores, and significantly longer vehicle following distances. Additionally, all participants in the trained group reported that their real world driving behaviour had improved. No significant training effects were found for the other measures. The results suggest that the course can improve key behaviours associated with crash risk.