Killer crashes: Fatal road traffic accidents in the UK

Road traffic accidents are responsible for over 3000 deaths per year in the UK, according to Department for Transport (2004a) figures. Although progress is being made in a number of areas, vehicle occupant fatalities have not been falling in line with casualty reduction targets for the year 2010. A sample of 1185 fatal vehicle occupant cases was considered, from ten UK police forces, from the years 1994-2005 inclusive. The main findings were: (1) over 65% of the accidents examined involved driving at excessive speed, a driver in excess of the legal alcohol limit, or the failure to wear a seat belt by a fatality, or some combination of these. (2) Young drivers have the great majority of their accidents by losing control on bends or curves, typically at night in rural areas and/or while driving for ‘leisure’ purposes. These accidents show high levels of speeding, alcohol involvement and recklessness. (3) Older drivers had fewer accidents, but those fatalities they were involved in tended to involve misjudgement and perceptual errors in ‘right of way’ collisions, typically in the daytime on rural rather than urban roads. Blameworthy right of way errors were notably high for drivers aged over 65 years, as a proportion of total fatal accidents in that age group.     

Older drivers’ road traffic crashes in the UK

A sample of over 2000 crashes involving drivers aged 60 years or over was considered, from three UK midland police forces, from the years 1994-2007 inclusive. Each case was summarized on a database including the main objective features (such as time and place), a summary narrative, a sketch plan and a list of explanatory factors.The main findings were that older drivers have significant problems with intersection collisions and failing to give right of way; these formed the largest single class of crashes in the sample. Possible behavioural explanations for this will be discussed, along with other findings regarding older driver blameworthiness, fatigue and illness, time of day factors, and ‘unintended accelerations’.     

The impact of driver education on self-reported collisions among young drivers with a graduated license

In this study, we assess the impact of driver education on the risk of collisions in a Graduated Licensing System (GLS). Ontario's GLS requires all new drivers to successfully pass through two stages of graduated license (referred to as G1 and G2, respectively) before full licensure is granted. Surveys of driving behaviour and related factors were administered to Grades 11 and 12 students with a graduated license in seven Ontario schools in 1996 and 1998. A total of 1533 students completed the survey in 2 years. Multivariate logistic regression analysis revealed a significantly lower odds of self-reported collision involvement among G1 license holders with driver education (OR: 0.31, 95% CI: 0.12-0.83). No significant effects were observed for G2 license holders. Other significant predictors of collisions include sex of driver, months of licensure and kilometers driven for G2 license holders. These results suggest that the impact of driver education may be dependent on the stage of driver learning in which it occurs.     

The role of motorcyclist and other driver behaviour in two types of serious accident in the UK

Motorcycle accidents have somewhat different characteristics from accidents involving other classes of road user. They include in particular 'right of way' accidents, and accidents involving loss of control on curves or bends. A sample of 1790 accident cases was considered, including 1003 in detail, from UK midland police forces, involving motorcyclists of all ages, and covering the years 1997-2002 inclusive. Significant differences were discovered in the sample with respect to types of accidents involving motorcyclists (and their blameworthiness). There seems to be a particular problem surrounding other road users' perception of motorcycles, particularly at junctions. Such accidents often seem to involve older drivers with relatively high levels of driving experience who nonetheless seem to have problems detecting approaching motorcycles. Motorcyclists themselves seem to have far more problems with other types of accident, such as those on bends or curves. The implications of these findings are discussed.     

Reducing traffic speed within roadwork sites using obtrusive perceptual countermeasures

Excessive speed is currently one of the primary contributory factors in traffic accidents within roadwork sites around the world. The present study evaluated two novel interventions designed to control traffic speed within an open road, roadwork site in New Zealand where drivers were required to decrease their speed from 100 to 50 km/h. Two different interventions were placed at the entrance to the work site and required drivers to pass between a 3.5 m wide passage of either evenly or decreasingly spaced cones. A multi-element baseline design was utilised. Both interventions were highly effective at reducing vehicle speed, with the greatest initial decrease in speed to 9.47 km/h below baseline for the uneven arrangement. Additionally, both arrangements more than halved the proportion of ‘dangerous’ speeders travelling faster than 20 km/h over the speed limit. The findings indicate that both arrangements of cones are effective, convenient, cost-effective strategies. It is concluded that, although both arrangements are highly effective, the use of unevenly-spaced cones is likely to most markedly reduce the number of speed-related accidents within open road roadwork zones. The findings are discussed in relation to the perceptual mechanisms by which transverse and peripheral stimuli influence speed perception and driver behaviour.     

Effects of roadside memorials on traffic flow

Despite their growing popularity in North America, little research has been conducted on understanding the effects of roadside memorials on drivers’ behaviour. In this study, we examined the short-term effects of roadside memorials on traffic speed and headways on a high speed intercity freeway as well as its long-term effect on traffic speed on a high speed urban freeway. Our study found that the placement of roadside memorials did not have any significant effect on traffic speeds or headways, either in the short or long term. Therefore, concerns about the negative effects on driver behaviour were not supported by this research, at least with regards to speeding and following too closely. However, no positive effects on safety were found either.     

Modernization of the Driver Behaviour Questionnaire

IntroductionThe current study builds on previous versions of the Driver Behaviour Questionnaire (DBQ) by incorporating a larger sample of driving behaviors targeting inattention, distraction, aggressive driving, and health related to aging. The goals of this study were to determine if the resulting factor structure was consistent with a more contemporary view of unsafe driving behaviors, and to determine whether scores on the factors could predict self-reported collisions and police citations.MethodsThe instrument was given to a sample of 3295 drivers ranging in age from 19 to 80+ years old. It was divided in two sections, the first to provide demographic information and driving history data and the second containing 105 driver behavior questions.ResultsAn exploratory factor analysis resulted in a 65-item scale organized in four factors. The factors were labeled tentatively as Inattention Errors, Age-Related Problems, Distraction and Hurry, and Aggressive Violations. Regression analyses showed that the factors were predictors of self-reported, at-fault collisions and police citations.Practical implicationsThe factor scores found in this research are consistent with a useful theoretical framework for understanding unsafe driver actions, and demonstrate some potential to identify several individual difference variables that predict self-reported collisions and citations.     

Modelling elastoplastic frictional collisions of ellipsoidal granules with collisional-SPH

The Collisional-SPH method models the combined evolution of deformation and frictional contact forces in elastoplastic granular collisions. However, there are many applications in which the granules are not spherical. In this paper, CSPH is extended to model an impact of an ellipsoidal granule on a flat deformable substrate. The CSPH spring-stiffness formulation is developed to account for the contact area eccentricity. Validation for different granule orientations and aspect-ratios are presented. The combined effect of substrate deformation and non-spherical granule shape on the contact-zone mechanics is investigated for different granule orientations and aspect ratios. It is found that the granule’s orientation and aspect ratio influences the interdependence between substrate deformation and contact-force distribution and should be accounted for in collision models.     

Post-licence driver education for the prevention of road traffic crashes: a systematic review of randomised controlled trials

The effectiveness of post-licence driver education for preventing road traffic crashes was quantified using a systematic review and meta-analyses of randomised controlled trials. Searches of appropriate electronic databases, the Internet and reference lists of relevant papers were conducted. The searches were not restricted by language or publication status. Data were pooled from 21 randomised controlled trials, including over 300,000 full licence-holding drivers of all ages. Nineteen trials reported subsequent traffic offences, with a pooled relative risk of 0.96 (95% confidence interval 0.94, 0.98). Fifteen trials reported traffic crashes with a pooled relative risk of 0.98 (0.96, 1.01). Four trials reported injury crashes with a pooled relative risk of 1.12 (0.88, 1.41). The results provide no evidence that post-licence driver education is effective in preventing road injuries or crashes. Although the results are compatible with a small reduction in the occurrence of traffic crashes, this may be due to selection biases or bias in the included trials.     

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.     

Work-related traffic crashes: a record linkage study

AIM: To examine the characteristics of work-related traffic crashes involving drivers in New South Wales (NSW), Australia. METHODS: Probabilistic data record linkage were used to merge police crash records and workers compensation data for the period 1998-2002. RESULTS: The record linkage identified 13,124 drivers who were injured or died as a result of work-related traffic crash in New South Wales over the 5-year period. Approximately three quarters of driver casualties occurred during commuting (74.8%) with the rest occurring in the course of work. Male drivers made up around three quarters of these crashes and 93% of those that resulted in a fatality. Transport workers were the most frequent victims of work-related crashes while on duty (20.8%), with drivers of heavy trucks representing about half (48%) of all fatalities resulting from on duty work-related crashes. Nearly 1 in 6 male drivers were speeding at the time of the crash (15%, 95% CI 14.2-15.7) compared to less than 1 in 10 female drivers (9%, 95% CI 8.3-9.8) of female drivers. Male drivers were also significantly more likely to be fatigued at the time of the crash 7.6% (95% CI 7.0-8.2) compared to females 4.2% (95% CI 3.7-4.8). No significant difference was observed in the proportion of crashes involving fatigue between on duty and commuting traffic crashes. CONCLUSIONS: The study demonstrates the value of record linkage techniques in addressing some of the limitations of work-related data systems and in providing a more complete picture of the circumstances of occupational road crashes.     

Looked-but-failed-to-see-errors in traffic

Danish studies of traffic accidents at priority intersections have shown a particular type of accidents. In these accidents a car driver supposed to give way has collided with a bicycle rider on the priority road. Often the involved car drivers have maintained that they did not see the bicycle until immediately before the collision even though the bicycle must have been clearly visible.

Similar types of accidents have been the subject of studies elsewhere. In literature they are labelled “looked-but-failed-to-see”, because it seems clear that in many cases the car drivers have actually been looking in the direction where the other parties were but have not seen (i.e. perceived the presence of) the other road user. This paper describes two studies approaching this problem.

One study is based on 10 self-reported near accidents. It does show that “looked-but-failed-to-see” events do occur, especially for well experienced drivers. The other study based on Gap Acceptance shows that the car driver acceptance of gaps towards cyclists depends on whether or not another car is present. Hypotheses for driver perception and for accident countermeasures are discussed.     

Validation of the Driver Behaviour Questionnaire in a representative sample of drivers in Australia

The Driver Behaviour Questionnaire (DBQ) is a widely used measure of driving behaviours that may increase a driver's risk of crash involvement. However, there are several different versions of the DBQ varying in terms of number of items and factor structure. The aim of the current research was to assess the construct validity of the popular 28-item four-factor DBQ solution in a representative sample of drivers in Australia. A further aim was to test the factorial invariance of the measure across gender, age and also between fleet and non-fleet drivers using multigroup confirmatory factor analyses. Data on a range of attitudes towards road safety were collected using an online survey. A stratified sampling procedure was undertaken to ensure the age, gender and location distributions of participants were representative of the Australian population. A total of 2771 responses were obtained from fully licensed motor vehicle drivers (male: 46%). Confirmatory factor analysis supported the 28-item four-factor DBQ in the Australian sample. The DBQ was also found to be gender-invariant and strong partial measurement invariance was found for drivers aged from 26 to 64, but not for younger (17–25) or older (65–75) drivers. Modifications to the DBQ suggest how the DBQ can be improved for use in these two age groups.     

The impact of work practices on fatigue in long distance truck drivers

Twenty seven professional truck drivers completed a 12 hour, 900 km trip under each of three driving regimes—a relay (staged) trip, a working hours regulated one-way (single) trip, and a one-way (flexible) trip with no working hours constraints. The results indicated that none of the driving regimes prevented fatigue and that the pattern of fatigue experienced during the trips appeared to be related to pretrip fatigue levels.     

Work-related versus non-work-related road accidents, developments in the last decade in France

The aim of this research was to analyze the changes that have affected work-related road accidents between 1997 and 2006, using police data. The study focused on drivers aged between 14 and 64 years. The characteristics considered were the age, gender, type of vehicle and occupation of the individuals involved and the location, time and severity of the accident. Two periods were compared, 1997-2000 and 2003-2006. Three types of journey were considered: while at work, commuting (going to and from work), and non-work-related.The percentage of all accidents which were work-related varied little over the decade (10% while at work and 18% while commuting). The accidents that occurred while at work still had the lowest fatality rates (1.4% among women and 3.4% among men in 2003-2006). Men accounted for the majority of the casualties: 90% of fatalities while at work and approximately 80% for the other types of journey. The greatest reduction took place in the number of motorists, and this has led to an increase in the proportion of motorized two-wheelers both while at work and while commuting. In the case of accidents while at work, the professional drivers still had the highest risk, craftsmen and shopkeepers were also at higher risk than manual workers of both genders and male employees. Extending analysis of this type to other European countries would be of major interest both for epidemiological monitoring and the prevention of occupational road accidents.     

Driver experience and cognitive workload in different traffic environments

How do levels of cognitive workload differ between experienced and inexperienced drivers? In this study we explored cognitive workload and driver experience, using a secondary task method, the peripheral detection task (PDT) in a field study. The main results showed a large and statistically significant difference in cognitive workload levels between experienced and inexperienced drivers. Inexperienced, low mileage drivers had on average approximately 250 milliseconds (ms) longer reaction times to a peripheral stimulus, than the experienced drivers. It would, therefore, appear that drivers with better training and experience were able to automate the driving task more effectively than their less experienced counterparts in accordance with theoretical psychological models. It has been suggested that increased training and experience may provide attention resource savings that can benefit the driver in handling new or unexpected traffic situations.     

Culture related to road traffic safety: A comparison of eight countries using two conceptualizations of culture

The majority of previous cross-country studies of human factors relevant to traffic safety have not operationalized and measured culture. Also studies in this vein have mostly been carried out in Europe and the United States. The aim of the study was to examine country cluster differences, based on the Culture's Consequences framework, in road traffic risk perception, attitudes towards traffic safety and driver behaviour in samples from Norway, Russia, India, Ghana, Tanzania, Uganda, Turkey and Iran. An additional aim was to examine cluster differences in road traffic culture as symbol use and to investigate whether this theoretical cultural framework predicts risk perception, attitudes towards traffic safety and driver behaviour in the country clusters. The sample consisted of a total of 2418 individuals who were obtained by convenience sampling in the different countries. The countries segmented into four Culture's Consequences clusters; Norway, Russia and India, Sub-Saharan Africa, and Near East countries. The findings showed that Norwegians reported overall safer attitudes towards traffic safety and driver behaviour than the remaining country clusters. Individuals in Africa reported the highest risk perception. The countries also differed substantially in road traffic culture as symbol use. Contrary to established cultural theory, prediction models revealed that cultural factors were stronger predictors of driver behaviour than of risk perception. Also, the social cognitive risk constructs (i.e. risk perception and attitudes) solely explained variance in driver behaviour in the Norwegian and Russia/India clusters. Previous empirical efforts, which aimed to demonstrate that culture is important for the risk perception criterion, may have focused on a criterion variable that is not strongly related to driver behaviour. Furthermore, countermeasures aimed to influence social cognition may have stronger applicability in countries with a more individualistic western cultural orientation.     

Personality domains and traits that predict self-reported aberrant driving behaviours in a southeastern US university sample

Personality traits are meaningful predictors of many significant life outcomes, including mortality. Several studies have investigated the relationship between specific personality traits and driving behaviours, e.g., aggression and speeding, in an attempt to identify traits associated with elevated crash risk. These studies, while valuable, are limited in that they examine only a narrow range of personality constructs and thus do not necessarily reveal which traits in constellation best predict aberrant driving behaviours. The primary aim of this study was to use a comprehensive measure of personality to investigate which personality traits are most predictive of four types of aberrant driving behaviour (Aggressive Violations, Ordinary Violations, Errors, Lapses) as indicated by the Manchester Driver Behaviour Questionnaire (DBQ). We recruited 285 young adults (67% female) from a university in the southeastern US. They completed self-report questionnaires including the DBQ and the Personality Inventory for DSM-5, which indexes 5 broad personality domains (Antagonism, Detachment, Disinhibition, Negative Affectivity, Psychoticism) and 25 specific trait facets. Confirmatory factor analysis showed adequate evidence for the DBQ internal structure. Structural regression analyses revealed that the personality domains of Antagonism and Negative Affectivity best predicted both Aggressive Violations and Ordinary Violations, whereas the best predictors of both Errors and Lapses were Negative Affectivity, Disinhibition and to a lesser extent Antagonism. A more nuanced analysis of trait facets revealed that Hostility was the best predictor of Aggressive Violations; Risk-taking and Hostility of Ordinary Violations; Irresponsibility, Separation Insecurity and Attention Seeking of Errors; and Perseveration and Irresponsibility of Lapses.