How to nudge drivers to reduce speed: The case of the left-digit effect

To decrease the negative consequences of a road crash, even a small reduction in driving speeds can make a significant difference. We examined the possible application of the left-digit effect as a nudge to reduce road speed. In the marketing field, this effect is based on reporting price tags that are characterized by a low leftmost number and a high rightmost number (e.g., a price tag of €14.99 rather than €15.00). We applied the same strategy to improve road safety. Participants were college students (43.75% female, mean age = 24.06 years in Study 1; 50% female, mean age = 23.53 years in Study 2) who were asked to drive in a simulator on a route that had both usual unmodified road signs (e.g., 50 km/h) and the same road signs increased or decreased by one unit (e.g., 49, 51 km/h). We compared the average median speeds in road segments with unmodified road signs with those in road segments with the corresponding modified signs. The average median speeds in the presence of a sign modified by the reduction of 1 km/h were significantly lower compared with the median average speeds recorded with unmodified signs. We showed that the application of psychological insights can reduce driving speeds and therefore increase road safety.     

The development and validation of a hazard perception test for Thai drivers

Thailand is a developing country with a high traffic accident fatality rate. However, few attempts have been made to understand crash risks in Thai drivers from a psychological perspective. The purpose of the present study was to develop and validate a latency-based hazard perception test for Thai drivers. The initial test comprised our full item pool of 77 clips containing traffic conflicts captured on video from the driver’s perspective on Thai roads. We evaluated the validity of this test by examining whether performance differed as a function of driving experience in a sample of 135 Thai drivers. We found that experienced drivers (n = 87) performed significantly better than novice drivers (n = 48) after adjusting for individual differences in computer mouse skill, mirroring crash risk differences between these groups. The final 30-item version of the test, which comprised the best items from the initial test, yielded novice/experienced driver differences with or without adjusting for computer mouse skill. These results offer preliminary support for the validity of the latency-based test as a measure of hazard perception ability in Thai drivers.     

Similarities between self-reported road safety behavior of teenage drivers and their perceptions concerning road safety behavior of their parents

The study investigated 401 19-year-olds, who were licensed car drivers in Lithuania. The focus of the survey was on the self-reported road safety behaviors of teenage drivers and their perceptions of their parents’ road safety behaviors, in order to assess behavioral similarities between teenagers and their parents. The survey also investigated whether parents and teenagers discuss issues of driving safely, and whether there is an association between these conversations and driving restrictions.According to teenagers’ reporting, road safety behavior of teenage drivers and their parents often is similar: most of them break the speed limit, drive when feeling fatigued, use a cell phone when driving, and do not fasten the seat belt as a passenger in the back seat. The study indicated that there is a positive moderate correlation between road safety behaviors of teenagers and their parents, as reported by the teenagers. A majority of teenagers report that they discuss road safety factors, driving safely and driving behavior with their parents. Based on teenager reports, the parents, who discuss road safety issues with their children, are more likely to apply restrictions on teenagers’ driving.     

Evaluating the impact of real-time coaching programs on drivers overtaking cyclists

Innovative motor insurance schemes involve the use of on-board devices to collect kinematic driving data as part of the so-called ‘Pay-How-You-Drive’ schemes, which charge premiums based on drivers’ behavior. Some of these schemes also involve on-board coaching programs, which give real-time feedback to users.Here, we aimed to investigate the influence of motor insurance on-board real-time coaching programs on drivers’ behavior while overtaking cyclists, as motor vehicle/bicycle interactions are a relevant issue in road safety. The tested programs give real-time feedback to users on their acceleration, promoting smoother and safer driving styles.Data were collected with a driving simulator experiment involving 67 young drivers. The experiment was divided into two trials: in the first, participants drove as normally as possible without receiving any type of feedback; in the second, which took place one month later, they received feedback based on their driving behavior. Using data from the first trial, participants were clustered (k-mean approximation) into two groups, according to their driving style (aggressive vs. defensive). For each group, half of the drivers received contingent positive feedback (when a smooth driving event occurred) and the other half received contingent negative feedback (when a harsh driving event occurred). Feedback was presented in the form of auditory cues (for half of one group) or as visual cues (for the others). Thus, there were eight groups based on driving style, feedback type, and feedback modality.Multiple kinematic variables were studied with mixed ANOVA, and included not only clearance distances, speeds, and acceleration, but also the chosen overtaking strategy (accelerative vs. flying). Driving style, gender, car usage, feedback type and modality were considered as factors in the analysis.Results showed that the coaching programs had a significant positive effect, in terms of safety, reducing acceleration and speeds during the overtaking and inducing drivers to adopt the safer accelerative strategy. It was also particularly effective in improving the performance of aggressive drivers. These results are of high interest for real-world applications because they were obtained with a general-purpose coaching program; conversely, it might be impractical to develop dedicate programs for specific situations such as drivers overtaking cyclists.     

Behavioral adaptations of human drivers interacting with automated vehicles

Advancements in technology are bringing automated vehicles (AVs) closer to wider deployment. However, in the early phases of their deployment, AVs will coexist and frequently interact with human-driven vehicles (HDVs). These interactions might lead to changes in the driving behavior of HDVs. A field test was conducted in the Netherlands with 18 participants focusing on gap acceptance, car-following, and overtaking behaviors to understand such behavioral adaptations. The participants were asked to drive their vehicles in a controlled environment, interacting with an HDV and a Wizard of Oz AV. The effects of positive and negative information regarding AV behavior on the participants’ driving behavior and their trust in AVs were also studied. The results show that human drivers adopted significantly smaller critical gaps when interacting with the approaching AV as compared to when interacting with the approaching HDV. Drivers also maintained a significantly shorter headway after overtaking the AV in comparison to overtaking the HDV. Positive information about the behavior of the AV led to closer interactions in comparison to HDVs. Additionally, drivers showed higher trust in the interacting AV when they were provided with positive information regarding the AV in comparison to scenarios where no information was provided. These findings suggest the potential exploitation of AV technology by HDV drivers.     

The implications of situation and route familiarity for driver-pedestrian interaction at uncontrolled mid-block crosswalks

Most routine daily trips take place along the same route, a fact that previous studies have not investigated together with the repeated situation of conflicting with other road users. Consequently, our study addresses driver behaviour by separating the driving experience into three categories: (i) drivers unfamiliar with the route, (ii) those route-familiar, and (iii) situation-familiar drivers. The specific case of driver-pedestrian interaction at uncontrolled mid-block crosswalks is investigated. A multi-level factorial experiment including (i) crosswalk design (linear sidewalk and curb extension), (ii) driver familiarity, and (iii) pedestrian time gap acceptance (4, 6, and 8 s) was conducted using a driving simulator. Fifty-two participants were divided into four groups and stratified by age, gender, and driving experience. The minimum instantaneous time to collision, post-encroachment time, maximum car deceleration, and maximum car speed were all used as surrogate safety measures (SSM).Route-familiarity led to higher speed, while situation-familiarity positively affected driving behaviour making drivers more inclined to decrease their speed at circa 100 m before a crosswalk. The curb extension layout enhanced pedestrian safety and mitigated any adverse effects due to familiarity, with a particularly relevant impact on SSM at low accepted time gaps for pedestrians. Situation- and route-familiarity treatment protocols lead to different behaviours among drivers, indicating a clear need to account for these two familiarity levels in experiments on safety-related countermeasures.     

Relationship between driving styles and biological behavior of drivers in negative emotional state

ObjectiveThis paper explores the links between driving style and the biological behavior of people while driving with dangerous negative emotions (such as anger, anxiety, and fear).BackgroundIt is highly important to study the behavior of humans from varying aspects to discover the factors affecting it. Driving style, as one of the critical aspects of the human factor, and biological behavior, as a factor influencing the performance of individuals, motivate us to examine the relationship between the two.MethodFor this purpose, a test was designed to record the biological signal data, namely, the Electrocardiogram (ECG), Electroencephalogram (EEG), Electromyogram (EMG), and Electrodermal activity (EDA), in a driving simulator with driving events prompting negative emotions. The Multidimensional Driving Style Inventory (MDSI) was employed to determine the driving style of participants.ResultsCorrelation analysis was engaged for data analysis. The results showed, firstly, a significant relationship between the participants’ driving style and their biological behavior and, secondly, the highest correlation between the EEG signal and driving style. Moreover, participants with a nervous and anxious style showed maximum change in biological behavior, while those with a reckless style displayed minimum alterations in biological behavior at the time of unpleasant events during driving.ConclusionConduction of such research can help better understand the behavior of different people while facing unpleasant driving events.     

Approaching to a structural model of impulsivity and driving anger as predictors of risk behaviors in young drivers

Due to the high rates of traffic accidents in young drivers, psychology studies identify road anger as an important factor associated to risk driving behaviors, in order to know which psychological variables can predict road anger, the literature suggest impulsivity as an individual condition related to anger. The objective of this research is to obtain an explanatory model of risk driving as a result of the relationship of impulsivity, road anger expression and the control of impulsivity and anger. A sample of 407 subjects, both sexes drivers were surveyed, obtaining a structural equation model with acceptable adjustment values. The model showed that control of impulsivity and anger predict impulsivity (β = −0.25) and physical expression of anger (β = −0.50), Impulsivity also showed predictive capacity towards the physical expression of anger (β = 0.29), and the physical expression of anger towards risk driving behaviors (β = 0.89). Due to the findings it is suggested the implementation of social programs that promote the development of anger regulatory skills and impulse control, as part of the preventive actions of road accidents.     

Transition patterns of driving style from a traditional driving environment to a connected vehicle environment: A case of an extra-long tunnel road

To provide a better understanding of individual driver’s driving style classification in a traditional and a CV environment, spatiotemporal characteristics of vehicle trajectories on a road tunnel were extracted through a driving simulator-based experiment. Speed, acceleration, and rate of acceleration changes are selected as clustering indexes. The dynamic time warping and k-means clustering were adopted to classify participants into different risk level groups. To assess the driver behavior benefits in a CV environment, an indicator BI (behavior indicator, BI) was defined based on the standard deviation of speed, the standard deviation of acceleration, and the standard deviation of the rate of acceleration change. Then, the index BI of each driver was calculated. Furthermore, this paper explored driving style classification, not in terms of traditional driving environment, but rather the transition patterns from a traditional driving environment to a CV environment. The results revealed that inside a long tunnel, 80 % of drivers benefited from a CV environment. Moreover, drivers might need training before using a CV system, especially female drivers who have low driving mileage. In addition, the results showed that the driving style of 69 % of the drivers’ transferred from a high risk-level to a low risk-level when driving in a CV environment. The study results can be expected to improve driving training education programs and also to provide a valuable reference for developing individual in-vehicle human-machine interface projects and other proactive safety countermeasures.     

Drinking,drug use and road rage in Turkish drivers

Alcohol or drug use and road rage behaviors in drivers are threats to traffic safety. The purpose of this research is to examine the relationship between alcohol or drug use and aggression in Turkish drivers, and to evaluate the mediating role of driving anger in this relationship. 270 amateur and professional Turkish drivers (170 male, 100 female) have filled up Driving Anger Scale (DAS), Driver Aggression Indicators Scale (DAIS), Alcohol Use Disorders Identification Test (AUDIT) and the Questionnaire Form. 15.9% of the participants scored 8 and higher on the AUDIT scale (alcohol problem). The most prevalent substance is cannabis, used at least once in a lifetime (20%). The results of mediated regression analysis indicates that driving anger has an increasing mediating role in the relationship between alcohol use and driver aggression. Due to limitations in the data, we could not reveal the relationship between substance use and driver aggression. These findings have led us to think that drinking use may contribute to being a perpetrator and/or a victim of the road rage. Taking precautions against drinking driving and road rage and going over the current implementations is important in order to create a safer traffic environment. Scientific researches carried out in this field must aim to provide the desired efficiency on prevention and intervention programs that reduce the prevalance of such dangerous acts.     

Associations between self-reported mindfulness,driving anger and aggressive driving

Anger and aggression on the roads is associated with how drivers evaluate the driving situation and the behaviour of other drivers. Consequently, both can be exacerbated when these evaluations are made superficially and/or when drivers have pre-existing negative schemas regarding certain types of road situations or users. Mindfulness is likely to have negative associations with anger and aggression because it promotes opposing appraisals. That is, it encourages emotion-regulation and involves acceptance of, but not reaction to, the current situation. To examine these associations, a total of 309 drivers responded to an online questionnaire assessing mindfulness, driving anger and aggressive driving. The results showed that mindfulness shared negative relationships with driving anger and self-reported aggressive driving. However, when these relationships were examined simultaneously using Structural Equation Modelling, mindfulness was found to relate only to anger and this, in turn, predicted aggressive driving. Further analysis showed that driving anger mediates the relationship between mindfulness and aggressive driving. These results suggest that mindfulness training may provide a promising intervention for drivers prone to driving anger and subsequent aggression.     

Effectiveness of the compensatory strategy adopted by older drivers: Difference between professional and non-professional drivers

It has been a controversial issue for the effect of ageing population on driving safety. Apparently, drivers’ physiological and cognitive performances deteriorate with age. However, older drivers may compensate for the elevated risk by adjusting their behaviors, known as compensatory strategy. Despite the extensive research on this topic, the compensatory strategy of older professional drivers is not well understood since many studies focused on the differences in compensatory behavior between older and young drivers. Professional drivers tend to be more skillful and able to cope with the unfavorable driving environments, thus presenting a higher capability to mitigate the risk. This study attempts to examine the compensatory behavior and its safety effect amongst older professional drivers, as compared to those of older non-professional drivers, using the driving simulator approach. In the driving simulator experiment, participants were asked to follow a leading vehicle for one hour, and two sudden brake events were presented. 41 (mid-aged and older) drivers completed the driving tests. Each participant was required to complete a car-following test, either under high or low traffic flow conditions. Performance indicators include driving capability (i.e. lateral control, longitudinal control, and brake reaction time) and compensatory behavior (i.e. average speed, and time headway). Additionally, two modified traffic conflict measures: time exposed time-to-collision (TET) and time integrated time-to-collision (TIT) are applied to indicate the traffic conflict risk. The random parameter Tobit models were estimated to measure the association between conflict risk and driver attributes, and random intercept models were used to assess other driving performance indicators. Results show that despite the impaired lateral control performance and longer brake reaction time of older drivers, the likelihood of severe traffic conflict of older drivers is lower than that of mid-aged drivers. Furthermore, though both older professional and older non-professional drivers adopted longer time headway, the reduction in the risk of severe traffic conflict is more profound among the older professional drivers. Such findings suggest that older professional drivers are more capable of mitigating the possible collision risk by adopting the compensatory strategy, as compared to older non-professional drivers. This justifies the existence of compound effect by the compensatory strategy of older driver and better driving skills of professional driver. This research provides useful insights into driver training and management strategies for employers, as older drivers would become a major cohort in the transportation industry.     

Bicycle fatalities: Trends in crashes with and without motor vehicles in The Netherlands

Boufous and Olivier (2015) recently found an increasing trend of police-reported cyclist deaths in single-vehicle crashes while a decreasing trend was found for fatal bicycle-motor vehicle crashes. This study sets out to conduct the same trend analyses for the Netherlands using causes of death statistics. The results show that for 1996–2014, the number of cyclist deaths in motor vehicle collisions per km cycled (i.e. the risk) has declined by 3.8% per annum (95% CI: −4.6%, −3.0%) while the risk of cyclist deaths in crashes without motor vehicles increased by 7.0% per annum (95% CI: 5.5%, 8.7%). The large majority of cyclist deaths at the beginning of the study period were due to bicycle-motor vehicle crashes. By 2014, however, the share with motor vehicles was only slightly higher than the share without motor vehicles. We also conducted trend analyses controlling for age by stratifying into nine age groups. After controlling for age, the average annual decrease of cyclist deaths in crashes with motor vehicles was 5.4% (95% CI: −6.0% to − 4.7%). The average annual increase of deaths in crashes without motor vehicles was 4.4% (95% CI: 3.1–5.7%). These trends are more favourable than those without controlling for age which can be explained by more cycling among the elderly who have an elevated risk. We conclude that, similar to Australia, cyclist deaths following motor vehicle crashes in the Netherlands have decreased while deaths without motor vehicles have increased.     

The ability of young,middle-aged and older drivers to inhibit visual and auditory distraction in a driving simulator task

Driver distraction is one major cause of road traffic accidents. In order to avoid distraction-related accidents it is important to inhibit irrelevant stimuli and unnecessary responses to distractors and to focus on the driving task, especially when unpredictable critical events occur. Since inhibition is a cognitive function that develops until young adulthood and decreases with increasing age, young and older drivers should be more susceptible to distraction than middle-aged drivers. Using a driving simulation, the present study investigated effects of acoustic and visual distracting stimuli on responses to critical events (flashing up brake lights of a car ahead) in young, middle-aged, and older drivers. The task difficulty was varied in three conditions, in which distractors could either be ignored (perception-only), or required a simple response (detection) or a complex Go-/NoGo-response (discrimination). Response times and error rates to the critical event increased when a simultaneous reaction to the distractor was required. This distraction effect was most pronounced in the discrimination condition, in which the participants had to respond to some of the distracting stimuli and to inhibit responses to some other stimuli. Visual distractors had a stronger impact than acoustic ones. While middle-aged drivers managed distractor inhibition even in difficult tasks quite well (i.e., when responses to distracting stimuli had to be suppressed), response times of young and old drivers increased significantly, especially when distractor stimuli had to be ignored. The results demonstrate the high impact of distraction on driving performance in critical traffic situations and indicate a driving-related inhibition deficit in young and old drivers.     

Anger,aggression and road rage behaviour in Malaysian drivers

This study tested the four factor structure of the Driving Anger Expression Inventory (DAX) in a sample of young Malaysian drivers and the relationship these factors had with several other variables. Confirmatory Factor Analysis broadly supported the four factor solution of the DAX, being: Personal Physical Aggressive Expression, Use of a Vehicle to Express Anger, Verbal Aggressive Expression and Adaptive/Constructive expression. The short version of the Driving Anger Scale was positively correlated with the three types of aggressive responses and not surprisingly with a variable comprised of all three types of aggressive responses (Total Aggressive Expression). Total Aggressive Expression was higher for males and negatively related to age, years licensed and slower preferred driving speed. All three of the aggressive forms of expression had significant relationships with crash-related conditions, such as: loss of concentration, losing control of their vehicle, having received a ticket and involvement in near-misses. In particular, all three of the aggressive forms of expression had significant relationships with losing control of the vehicle and Total Aggressive Expression was correlated with all crash-related conditions. In addition, Personal Physical Aggressive Expression and Total Aggressive Expression were both significantly related to crash involvement.     

Mobile phone use while driving in Finland

Mobile phones represent one of the most common distractions for drivers and phone use while driving is particularly problematic in Finland. The aim of this research was to explore the Finnish sample of responses from ESRA2 (E-Survey of Road users' Attitudes) with a specific focus on the distracting behaviours related to mobile phone usage while driving. ESRA2 data is derived from online surveys amongst a representative sample of the adult populations in each participating country. In total a sample of 994 responses were collected in Finland for ESRA2, which included 703 responses from participants who held a driver’s licence and reported driving a car in the 30 days prior to the survey.The results provide evidence of the problematic usage of mobile phones while driving in Finland. Mobile phone use was considered across three specific types of usage: (1) handheld phone calls while driving; (2) handsfree phone calls while driving; (3) texting, emailing or social media use while driving. Almost half (49.4 %) of the sample reported using a handheld mobile phone to make a call while driving at least once in the 30 days prior to the survey. A similar percentage (41.4 %) of the sample had used a phone hands-free and 35.6 % had texted, emailed, or used social media.The study highlights how mobile phone usage is a complex and multifaceted issue and that there are a broad range of underlying factors that influence mobile phone usage depending on the way in which people engage with their mobile phone while driving. The findings suggest that a systematic approach to reducing mobile phone distraction is needed that addresses the issue through a combination of legislation, enforcement, and education.     

Car-following behavioural adaptation when driving next to automated vehicles on a dedicated lane on motorways: A driving simulator study in the Netherlands

Automated vehicles (AVs) are expected to improve traffic flow efficiency and safety. The deployment of AVs on motorways is expected to be the first step in their implementation. One of the main concerns is how human drivers will interact with AVs. Dedicating specific lanes to AVs have been suggested as a possible solution. However, there is still a lack of evidence-based research on the consequence of dedicated lanes for AVs on human drivers’ behavior. To bridge this research gap, a driving simulator experiment was conducted to investigate the behavior of human drivers exposed to different road design configurations of dedicated lanes on motorways. The experiment sample consisted of 34 (13 female) licensed drivers in the age range of 20–30. A repeated measures ANOVA was applied, which revealed that the type of separation between the dedicated lane and the other lanes has a significant influence on the behavior of human drivers driving in the proximity of AV platoons. Human drivers maintained a significantly lower time headway (THW) when driving in the proximity of a continuous access dedicated lane as compared to a limited-access dedicated lane with a guardrail separation for AV platoons. A similar result was found for the limited-access dedicated lane in comparison to the limited-access dedicated lane with guardrail separation. Moreover, the results regarding the empirical relationships between THW and sociodemographic variables indicate a significant THW difference between males and females as well as a significant inverse relationship between THW and the years of driving experience.