Commentary training improves responsiveness to hazards in a driving simulator

Can commentary driving produce safer drivers? Producing a verbal commentary of potential hazards during driving has long been considered by the police to improve hazard perception skills. In this study we investigated whether learner drivers would benefit from being trained to produce a commentary drive. All learners were initially assessed on a virtual route in a driving simulator that contained 9 hazards. One group of drivers was then trained in commentary driving, and their subsequent simulated driving behaviour was compared to a control group. The results showed that the trained group had fewer crashes, reduced their speed sooner on approach to hazards, and applied pressure to the brakes sooner than untrained drivers. Conversely the untrained drivers' behaviour on approach to hazards was symptomatic of being surprised at the appearance of the hazards. The benefit of training was found to be greater for certain types of hazard than others.

Speeding and the time-saving bias: how drivers' estimations of time saved in higher speed affects their choice of speed

According to the time-saving bias, drivers overestimate the time saved when increasing from an already relatively high speed and underestimate the time saved when increasing from a relatively low speed. This study examined the effect the time-saving bias may have on drivers' choice of speed using hypothetical situations. Drivers were presented with a situation involving acceleration from a relatively low speed in order to arrive at a destination on time and were asked to estimate the time that could be saved by increasing to higher speeds. Drivers also estimated the speed required for arriving on time, the speed they would personally choose and the speed they believed other drivers would opt for in such a situation. Results showed that drivers indeed underestimated the time that could be saved by increasing from a low speed. In addition, drivers who showed a high time-saving bias (above median) indicated notably higher speeds in all three categories above and their indicated speeds exceeded the speed limit more frequently. These findings suggest that the time-saving bias may help explain why drivers, in some situations, prefer an overly high speed and violate the legal speed limit.

Hazard perception as a function of target location and the field of view

A typical hazard perception test presents participants with a single-screen view of the road ahead. This study assessed how increasing this field of view would affect hazard perception abilities. Drivers were shown video clips of driving situations containing at least one hazard either on a single screen, or with the addition of side views on two separate but adjacent screens that extended the perceived worldview to approximately 180 degrees. Mirror information was also included to allow information from behind the vehicle to be attended. Participants were instructed to press a button as soon as they saw a hazard. Faster response times were found for hazards that appeared in the centre of the central screen, than in the periphery of the central screen, with hazards that first appeared in the lateral screens responded to slowest. Additionally, responses to the hazards were faster and were more likely to occur in the three-, as compared to the single-screen condition. These results suggest that providing participants with a wider field of view, which includes more environmental cues that are related to the relevant hazardous situation increases their ability to detect hazards, and some limited support to that providing them with a wider view increases this ability even when all hazard-relevant information appear only in the central screen. A number of reasons for the three-screen advantage are discussed. This study suggests that even responses to central hazards may be under-estimated in a typical single-screen hazard perception test, and that improvements can be made for new hazard perception tests, by including visual information from the side and from behind the driver. This new methodology not only allows testing hazard perception skills in a potentially more immersive and realistic environment, but also enables to create hazard perception clips that cannot be realised in a typical single-screen test.

The effect of alcohol, THC and their combination on perceived effects, willingness to drive and performance of driving and non-driving tasks

BACKGROUND

Driving under the influence of drugs (DUID) is one of the main causes of car accidents. Alcohol and marijuana are the most popular drugs among recreational users. Many classify these drugs as "Light" drugs and therefore allow themselves to drive after consuming them.

OBJECTIVE

The study had two main objectives: 1) to investigate the effect of alcohol (BAC=0.05%), THC (13 mg) and their combination on driving and non-driving tasks. 2) to investigate the extent to which people are willing to drive based on their subjective sensations and their perceived effects of the drugs.

METHOD

7 healthy men and 5 healthy women, ages 24-29, all recreational users of alcohol and marijuana, completed 5 experimental sessions. Sessions included: drinking and smoking placebo, drinking alcohol and smoking placebo, drinking placebo and smoking THC, drinking alcohol and smoking THC, drinking placebo and smoking placebo 24 hours after drinking alcohol and smoking THC. Three types of measures were used: subjective perceptions (with questionnaires), performance parameters of the driving and non-driving tasks (arithmetic task and a secondary target detection task) and physiological changes (heart rate).

RESULTS

Overall, the combination of alcohol and THC had the most intense effect after intake. This effect was reflected in performance impairments observed in the driving and non-driving tasks, in the subjective sensations after intake, and in the physiological measures. Despite significant differences in the size of the effects after the various treatments, there were no differences in the distances subjects were willing to drive while under the influence on each of the treatments.

The blind date: the effects of change blindness, passenger conversation and gender on looked-but-failed-to-see (LBFTS) errors

This study examined situations where drivers looked-but-failed-to-see (LBFTS) hazards, and whether passenger conversation and gender affected hazard detection rates. To reliably produce LBFTS errors, 40 young drivers (M=20.3) encountered motorcycles and pedestrians while making left turns in the University of Calgary Driving Simulator (UCDS). Prior to turn initiation the UCDS screens flickered using an extension of change blindness methods. In addition, drivers either drove alone or conversed with an attractive confederate passenger. Measures of LBFTS errors, hazard detection and social factors were analyzed. Higher rates of LBFTS errors and hazard detection occurred while conversing than while driving alone. A discriminant function analysis (DFA) using conversation and gender as predictors accurately classified LBFTS errors. Higher passenger attraction and higher extroversion were related to critical events being missed. The basis of LBFTS errors in divided and selective attention and classification implications are discussed.

Bicycle injuries in children: an analysis based on demographic density

INTRODUCTION

The purpose of this study was to investigate the characteristics and the outcome of bicycle injuries in paediatric patients according to the living environment, and to create guidelines for injury prevention.

PATIENTS

The evaluation was performed in part based on hospital database of 1803 in- and out-patient children treated at the Paediatric Surgical Department of Pécs/Hungary between 2000 and 2006, and at the Department of Paediatric Surgery at the Heim Pal Hospital Budapest between 2004 and 2006. Additionally questionnaires were mailed to the patients' families to gain follow-up information. We analysed three groups according to demographic density (village, midsize town and large town).

RESULTS

We found, that poor road quality played an important role as a contributing factor of injuries in villages. The number of bicycle spoke-injuries was higher in villages (13%), than in midsize towns (4.6%) and the large town (9.9%). In villages, 5% of children injured wore a helmet; this rate was 9% in midsize towns and 9.1% in the large town. Head injury was more common in villages, while in midsize towns and the large town arm injuries proved to be predominant.

DISCUSSION

Prevention strategies targeting bicycle injuries in children should take into account the population density. This analysis revealed a substantial difference in the use of safety devices, and in the characteristics of injuries occurring in villages, indicating that there is a need for special attention regarding this higher risk population.

Adolescent drivers' perceptions of the advantages and disadvantages of abstention from in-vehicle cell phone use

Driver in-vehicle cell phone use presents a dangerous distraction for adolescent drivers for whom motor vehicle crashes represents the leading cause of death. We used the National Young Driver Survey (NYDS), a nationally representative (N=5665) cross-sectional study of adolescent driving behavior, to examine potential psychosocial correlates of cell phone use while driving (CPWD). Results indicated that stronger beliefs about the advantages of abstention from CPWD were associated with less frequent CPWD, adjusted OR: 0.46 95% [CI: 0.40-0.53]), while stronger beliefs about the disadvantages of abstention were associated with more frequent CPWD, adjusted OR: 1.41 95% CI: [1.21-1.64]. In the absence of strong advantage beliefs, disadvantage beliefs did not have a meaningful association with less frequent CPWD. Almost 30% of adolescents held weaker advantage beliefs coupled with stronger disadvantage beliefs, placing them most at risk. These findings offer guidance for a wide range of intervention and health promotion efforts.

Alcohol-related impairment in the Lane Change Task

The Lane Change Task was developed to provide an objective safety criterion for the assessment of driver distraction by in-vehicle information systems (IVIS). It consists of two basic driving tasks, namely lane keeping and lane changes. The LCT has been shown to reliably detect distraction from driving. As this test becomes increasingly important for the assessment of safety the validity of the LCT is crucial. In order to examine this further, the effect of an alcohol intoxication of 0.08 g/dl on the performance in the LCT was examined in the present study as the negative effects of alcohol on driving are well known. Twenty-three participants were tested under alcohol and placebo in a cross-over design measuring different performance indicators in the LCT. There were significant effects of alcohol during the lane keeping phase. However, these were much smaller than those typically found with distracting secondary tasks. The lane change phase was only marginally affected by alcohol. This result gives rise to some caution for interpreting effects in the LCT. The LCT is well able to detect distraction, as other studies have shown. However, our study with intoxicated participants shows that a small effect in the LCT does not necessarily mean that this condition does not impair driving.

The social cognitive determinants of offending drivers' speeding behaviour

The efficacy of an extended theory of planned behaviour (TPB) was tested in relation to offending drivers' (N=1403) speeding behaviour. Postal questionnaires were issued at Time 1 to measure intention, instrumental and affective attitude, subjective and descriptive norm, self-efficacy, perceived controllability, moral norm, anticipated regret, self-identity, and past speeding behaviour. At Time 2 (6 months later), subsequent speeding behaviour was measured, again using self-completion postal questionnaires. The extended TPB accounted for 68% of the variation in intention and 51% of the variation in subsequent behaviour. The independent predictors of intention were instrumental attitude, affective attitude, self-efficacy, moral norm, anticipated regret and past behaviour. The independent predictors of behaviour were intention, self-efficacy, anticipated regret and past behaviour. Theoretical and practical implications of the findings are discussed in relation to targeting road safety interventions.

Examining the influence of aggressive driving behavior on driver injury severity in traffic crashes

In this paper, we capture the moderating effect of aggressive driving behavior while assessing the influence of a comprehensive set of variables on injury severity. In doing so, we are able to account for the indirect effects of variables on injury severity through their influence on aggressive driving behavior, as well as the direct effect of variables on injury severity. The methodology used in the paper to accommodate the moderating effect of aggressive driving behavior takes the form of two models--one for aggressive driving and another for injury severity. These are appropriately linked to obtain the indirect and direct effects of variables. The data for estimation is obtained from the National Motor Vehicle Crash Causation Study (NMVCCS). From an empirical standpoint, we consider a fine age categorization until 20 years of age when examining age effects on aggressive driving behavior and injury severity. There are several important results from the empirical analysis undertaken in the current paper based on post-crash data collection on aggressive behavior participation just prior to the crash and injury severity sustained in a crash. Young drivers (especially novice drivers between 16 and 17 years of age), drivers who are not wearing seat belt, under the influence of alcohol, not having a valid license, and driving a pick-up are found to be most likely to behave aggressively. Situational, vehicle, and roadway factors such as young drivers traveling with young passengers, young drivers driving an SUV or a pick-up truck, driving during the morning rush hour, and driving on roads with high speed limits are also found to trigger aggressive driving behavior. In terms of vehicle occupants, the safest situation from a driver injury standpoint is when there are two or more passengers in the vehicle, at least one of whom is above the age of 20 years. These and many other results are discussed, along with implications of the result for graduated driving licensing (GDL) programs.

That's close enough--a threshold effect of time headway on the experience of risk, task difficulty, effort, and comfort

Subjective impressions of task difficulty, risk, effort, and comfort are key variables of several theories of driver behaviour. A point of difference between many of these theories is not only the importance of these variables, but also whether they are continuously present and monitored or only experienced by individuals at certain critical points in the driving task. Both a threshold relationship and evidence of constant monitoring of risk and task difficulty have been found for speed choice. In light of these conflicting findings this study seeks to examine a different part of the driving task, the choice of time headway. Participants (N=40, aged 19 to 30) drove in a simulator behind a vehicle travelling at 50 km/h at set time headways ranging from 0.5 seconds to 4.0 seconds. After each drive ratings of task difficulty, risk, comfort, and effort were collected. In addition participants were asked to drive at the time headway they preferred. In order to assess familiarity participants also drove on both the left and right hand side of the road and the role of driving experience was also examined. The results show support for a threshold awareness of task difficulty, risk, effort, and comfort in relation to time headway. Participant's ratings of these variables tended to be low or nil at large time headways, but then around the 2.0 second mark began to noticeably increase. Feelings of task difficulty, risk, and effort were also found to be highly correlated with each other. No effect of driving experience or side of the road was found.

Speed cameras in Sweden and Victoria, Australia--a case study

In this article, the ideas behind two different speed camera systems in Australia, Victoria, and Sweden are explored and compared. The study shows that even if the both systems technically have the same aim--to reduce speeding--the ideas of how that should be achieved differ substantially. The approach adopted in Victoria is based on the concept that speeding is a deliberate offence in which a rational individual wants to drive as fast as possible and is prepared to calculate the costs and benefits of his behaviour. Therefore, the underlying aim of the intervention is to increase the perceived cost of committing an offence whilst at the same time decrease the perceived benefits, so that the former outweigh the latter. The Swedish approach, on the other hand, appears to be based on a belief that road safety is an important priority for the road users and one of the reasons to why road users drive too fast is lack of information and social support. In order to evaluate road safety interventions and how their effects are created together with the ambition to transfer technology, there is a need for a comprehensive understanding of the systems and their modi operandi in their specific contexts. This study has shown that there are major differences between the ideas behind the two speed camera programs in Victoria, Australia and Sweden and that these ideas have an impact on the actual design of the different systems and how these are intended to create road safety effects.

Improving older drivers' hazard perception ability

One reason that older drivers may have elevated crash risk is because they anticipate hazardous situations less well than middle-aged drivers. Hazard perception ability has been found to be amenable to training in young drivers. This article reports an experiment in which video-based hazard perception training was given to drivers who were between the ages of 65 and 94 years. Trained participants were significantly faster at anticipating traffic hazards compared with an untrained control group, and this benefit was present even after the authors controlled for pretraining ability. If future research shows these effects to be robust, the implications for driver training and safety are significant.

Heart rate responses to standardized trauma-related pictures in acute posttraumatic stress disorder

Physiological responses to trauma reminders are one of the core symptoms of posttraumatic stress disorder (PTSD). Nevertheless, screening measures for PTSD largely rely on symptom self-reports. It has been suggested that psychophysiological assessments may be useful in identifying trauma survivors with PTSD (Orr and Roth, 2000). This study investigated whether heart rate (HR) responses to standardized trauma-related pictures distinguish between trauma survivors with and without acute PTSD. Survivors of motor vehicle accidents or physical assaults (N=162) watched standardized trauma-related, generally threatening and neutral pictures at 1 month post-trauma while their ECG was recorded. At 1 and 6 months, structured clinical interviews assessed PTSD diagnoses. Participants completed self-report measures of PTSD severity and depression, peritraumatic responses, coping behaviors and appraisals. Trauma survivors with acute PTSD showed greater HR responses to trauma-related pictures than those without PTSD, as indicated by a less pronounced mean deceleration, greater peak responses, and a greater proportion showing HR acceleration of greater than 1 beat per minute. There were no group differences in HR responses to generally threatening or neutral pictures. HR responses to trauma-related pictures contributed to the prediction of PTSD diagnosis over and above what could be predicted from self-reports of PTSD and depression. HR responses to trauma-related pictures were related to fear and data-driven processing during the trauma, safety behaviors, suppression of trauma memories, and overgeneralized appraisals of danger. The results suggest that HR responses to standardized trauma-related pictures may help identify a subgroup of patients with acute PTSD who show generalized fear responses to trauma reminders. The early generalization of triggers of reexperiencing symptoms observed in this study is consistent with associative learning and cognitive models of PTSD.

Effectiveness of social norms media marketing in reducing drinking and driving: A statewide campaign

This research evaluated the efficacy of a high-intensity social norms media marketing campaign aimed at correcting normative misperceptions and reducing the prevalence of drinking and driving among 21-to-34-year-olds in Montana. A quasi-experimental design was used, such that regions of Montana were assigned to one of three experimental groups: social norms media marketing campaign, buffer, and control. Four random samples of Montanans between the ages of 21 and 34 were assessed at four time points over 18 months via phone surveys. Findings suggest that the social norms media campaign was successful at exposing the targeted population to social norms messages in the counties within the intervention region. Moreover, results demonstrate the campaign reduced normative misperceptions, increased use of designated drivers, and decreased drinking and driving among those young adults in counties within the intervention region. Social norms media marketing can be effective at changing drinking-related behaviors at the population level. This research provides a model for utilizing social norms media marketing to address other behaviors related to public health.

Tension pneumopericardium: case report

Pneumopericardium is defined as the presence of air within the pericardial space. It is an uncommon complication of blunt or penetrating chest trauma and may also occur iatrogenically. 'Simple' pneumopericardium produces no discernible circulatory compromise; however, simple pneumopericardium may progress rapidly to produce cardiovascular compromise or circulatory collapse, when it is termed 'tension' pneumopericardium. Tension pneumopericardium requires emergent drainage of the pericardial sac. Failure to achieve rapid effective drainage may result in cardiac arrest. Drainage of the pericardial sac may be achieved by either percutaneous or open drainage technique. Formation of a sub-xiphoid pericardial window has been advocated as a rapid and effective means of achieving open drainage. This may be carried out at the bedside with minimal equipment, and the authors advocate this technique as the preferred option for achieving drainage. This case demonstrates the rapid and dramatic deterioration to cardiac arrest of a multiply injured trauma patient with radiologically confirmed pneumopericardium. The effectiveness of open drainage via a sub-xiphoid pericardial window at the bedside with resultant return of spontaneous circulation is also shown. In addition, the pathogenesis and natural history of this uncommon condition are reviewed and the options for management are discussed.

Road safety research in China: review and appraisal

OBJECTIVE

This study explored two major problems of China's traffic and reviewed the human factors research in road safety published in Chinese journals.

METHODS

A comprehensive search of Chinese journals related to road safety was conducted. Forty-three studies were found and reviewed in this article.

RESULTS

One problem is pedestrians and bicyclists crossing streets and their interactions with vehicle drivers. The other is aggressive driving, such as frequently changing lanes, tailgating, moving forward, and obstructing the path of others. All the reviewed studies were classified into 4 categories according to the research topics: driver capacity, driving style, driver fatigue, and traffic accidents. Driver capacity research studied Chinese drivers' physical and mental abilities, including information processing, vision, reaction, attention distribution, and mental workload, and their differences between accident and non-accident drivers. Driving style research explored the influence of drivers' personality traits, psychological stress, temperament types, and mood on their behavior and accident involvement. It was found that accident and non-accident drivers were significantly different in sympathy, perseverance, aggressiveness, cooperativeness, and anxiety. In studies of driver fatigue, researchers investigated the impact of driving time, time of a day, road environment, age, and driving experience on drivers' capacities and performance. The characteristics of China's traffic accidents and road alignment of accident-prone roads were analyzed in the traffic accident research.

CONCLUSIONS

We determined the gap between existing research and the two salient problems of China's traffic and pointed out directions for future research.

The development and validation of two complementary measures of drivers' hazard perception ability

Hazard perception in driving involves a number of different processes. This paper reports the development of two measures designed to separate these processes. A Hazard Perception Test was developed to measure how quickly drivers could anticipate hazards overall, incorporating detection, trajectory prediction, and hazard classification judgements. A Hazard Change Detection Task was developed to measure how quickly drivers can detect a hazard in a static image regardless of whether they consider it hazardous or not. For the Hazard Perception Test, young novices were slower than mid-age experienced drivers, consistent with differences in crash risk, and test performance correlated with scores in pre-existing Hazard Perception Tests. For drivers aged 65 and over, scores on the Hazard Perception Test declined with age and correlated with both contrast sensitivity and a Useful Field of View measure. For the Hazard Change Detection Task, novices responded quicker than the experienced drivers, contrary to crash risk trends, and test performance did not correlate with measures of overall hazard perception. However for drivers aged 65 and over, test performance declined with age and correlated with both hazard perception and Useful Field of View. Overall we concluded that there was support for the validity of the Hazard Perception Test for all ages but the Hazard Change Detection Task might only be appropriate for use with older drivers.

Age, skill, and hazard perception in driving

This study examined the effects of age and driving experience on the ability to detect hazards while driving; namely, hazard perception. Studies have shown that young-inexperienced drivers are more likely than experienced drivers to suffer from hazard perception deficiencies. However, it remains to be determined if this skill deteriorates with advancing age. Twenty-one young-inexperienced, 19 experienced, and 16 elderly drivers viewed six hazard perception movies while connected to an eye tracking system and were requested to identify hazardous situations. Four movies embedded planned, highly hazardous, situations and the rest were used as control. Generally, experienced and older-experienced drivers were equally proficient at hazard detection and detected potentially hazardous events (e.g., approaching an intersection, pedestrians on curb) continuously whereas young-inexperienced drivers stopped reporting on hazards that followed planned, highly hazardous situations. Moreover, while approaching T intersections older and experienced drivers fixated more towards the merging road on the right while young-inexperienced drivers fixated straight ahead, paying less attention to potential vehicles on the merging road. The study suggests that driving experience improves drivers' awareness of potential hazards and guides drivers' eye movements to locations that might embed potential risks. Furthermore, advanced age hardly affects older drivers' ability to perceive hazards, and older drivers are at least partially aware of their age-related limitations.

Gender differences in factors predicting unsafe crossing decisions in adult pedestrians across the lifespan: a simulation study

Adult pedestrian accident data has demonstrated that the risk of being killed or seriously injured varies with age and gender. A range of factors affecting road crossing choices of 218 adults aged 17-90+ were examined in a simulation study using filmed real traffic. With increasing age, women were shown to make more unsafe crossing decisions, to leave small safety margins and to become poorer at estimating their walking speed. However, the age effects on all of these were ameliorated by driving experience. Men differed from women in that age was not a major factor in predicting unsafe crossing decisions. Rather, reduced mobility was the key factor, leading them to make more unsafe crossings and delay longer in leaving the kerb. For men, driving experience did not predict unsafe road crossing decisions. Although male drivers were more likely to look both ways before crossing than male non-drivers, the impact of being a driver had a negative effect in terms of smaller safety margins and delay in leaving the kerb. The implications of the different predictor variables for men and women for unsafe road crossing are discussed and possible reasons for the differences explored.

Self-reported road traffic violations in France and how they have changed since 1983

GOALS

The goal was to gain a picture of current driver behaviour, and of the links between committed violations and accident history. It was also to identify how driver behaviour has changed over the last 20 years.

METHODS

A questionnaire-based cross-sectional study of a sample of 1161 drivers about the frequency of violations and the perception of the dangers and penalties associated with them was used in 2005. Self-reported violations and mental representations were also compared to the results of Biecheler who used similar methods (Biecheler-Fretel, 1983).

RESULTS, CONCLUSIONS

Road traffic violations are frequent in France, particularly among male drivers. Several violations are linked with history of accidents in our sample. Frequently or fairly frequently exceeding the speed limit by 10 km/h (a violation reported by almost 53% of our sample), increases accident occurrence by a factor of 1.4. Progress in drivers' behaviour has been slow and nonuniform, and appears in part to be related to safety campaigns that have been run (seat belts, alcohol). The results could inform future campaigns. In particular, a campaign on the use of indicators would seem worthwhile.

Aberrant driving behaviors: a study of drivers in Beijing

The addition of massive numbers of new drivers with varied driving experience to roads in China suggests it is important to understand the nature of aberrant driving behaviors for this new set of drivers. A paper-based and an Internet survey were administered. Factor analysis produced a five-factor structure for each survey. The distinction between violations and errors indicated in previous studies was confirmed. The violations included emotional violations, risky violations and self-willed violations, and the errors included inexperience errors and distraction errors. In contrast to previous work, age was not found to be a good predictor of violations though driving experience was. Contrary to expectations, non-automotive (bicycle) roadway experience or level of driving training failed to predict poor driving behavior. On-road experience is the key to risk for China's drivers. Good agreement between the paper-based and Internet surveys indicate online surveys to be a feasible way to conduct research of driving behavior at low cost.