Are drivers aware of sleepiness and increasing crash risk while driving?

Drivers are advised to take breaks when they feel too tired to drive, but there is question over whether they are able to detect increasing fatigue and sleepiness sufficiently to decide when to take a break. The aim of this study was to investigate the extent to which drivers have access to cognitive information about their current state of sleepiness, likelihood of falling asleep, and the implications for driving performance and the likelihood of crashing. Ninety drivers were recruited to do a 2h drive in a driving simulator. They were divided into three groups: one made ratings of their sleepiness, likelihood of falling asleep and likelihood of crashing over the next few minutes at prompts occurring at 200s intervals throughout the drive, the second rated sleepiness and likelihood of falling asleep at prompts but pressed a button on the steering wheel at any time if they felt they were near to crashing and the third made no ratings and only used a button-press if they felt a crash was likely. Fatigue and sleepiness was encouraged by monotonous driving conditions, an imposed shorter than usual sleep on the night before and by afternoon testing. Drivers who reported that they were possibly, likely or very likely to fall asleep in the next few minutes, were more than four times more likely to crash subsequently. Those who rated themselves as sleepy or likely to fall asleep had a more than 9-fold increase in the hazards of a centerline crossing compared to those who rated themselves as alert. The research shows clearly that drivers can detect changes in their levels of sleepiness sufficiently to make a safe decision to stop driving due to sleepiness. Therefore, road safety policy needs to move from reminding drivers of the signs of sleepiness and focus on encouraging drivers to respond to obvious indicators of fatigue and sleepiness and consequent increased crash risk.

The effect of external non-driving factors, payment type and waiting and queuing on fatigue in long distance trucking.

INTRODUCTION: The aim of this study was to explore the effects of external influences on long distance trucking, in particular, incentive-based remuneration systems and the need to wait or queue to load or unload on driver experiences of fatigue. METHODS: Long distance truck drivers (n=475) were recruited at truck rest stops on the major transport corridors within New South Wales, Australia and asked to complete a survey by self-administration or interview. The survey covered demographics, usual working arrangements, details of the last trip and safety outcomes including fatigue experiences. RESULTS: On average drivers' last trip was over 2000 km and took 21.5 h to complete with an additional 6h of non-driving work. Incentive payments were associated with longer working hours, greater distances driven and higher fatigue for more drivers. Drivers required to wait in queues did significantly more non-driving work and experienced fatigue more often than those who did not. Drivers who were not paid to wait did the longest trips with average weekly hours above the legal working hours limits, had the highest levels of fatigue and the highest levels of interference by work with family life. In contrast, drivers who were paid to wait did significantly less work with shorter usual hours and shorter last trips. Multivariate analysis showed that incentive-based payment and unpaid waiting in queues were significant predictors of driver fatigue. CONCLUSIONS: The findings suggest that mandating payment of drivers for non-driving work including waiting would reduce the amount of non-driving work required for drivers and reduce weekly hours of work. In turn this would reduce driver fatigue and safety risk as well as enhancing the efficiency of the long distance road transport industry.

Initial development of a practical safety audit tool to assess fleet safety management practices.

Work-related vehicle crashes are a common cause of occupational injury. Yet, there are few studies that investigate management practices used for light vehicle fleets (i.e. vehicles less than 4.5 tonnes). One of the impediments to obtaining and sharing information on effective fleet safety management is the lack of an evidence-based, standardised measurement tool. This article describes the initial development of an audit tool to assess fleet safety management practices in light vehicle fleets. The audit tool was developed by triangulating information from a review of the literature on fleet safety management practices and from semi-structured interviews with 15 fleet managers and 21 fleet drivers. A preliminary useability assessment was conducted with 5 organisations. The audit tool assesses the management of fleet safety against five core categories: (1) management, systems and processes; (2) monitoring and assessment; (3) employee recruitment, training and education; (4) vehicle technology, selection and maintenance; and (5) vehicle journeys. Each of these core categories has between 1 and 3 sub-categories. Organisations are rated at one of 4 levels on each sub-category. The fleet safety management audit tool is designed to identify the extent to which fleet safety is managed in an organisation against best practice. It is intended that the audit tool be used to conduct audits within an organisation to provide an indicator of progress in managing fleet safety and to consistently benchmark performance against other organisations. Application of the tool by fleet safety researchers is now needed to inform its further development and refinement and to permit psychometric evaluation.

Characteristics of fatal motorcycle crashes into roadside safety barriers in Australia and New Zealand.

This paper reports on the findings of a retrospective case series study of fatal motorcyclist-roadside barrier collisions. Cases were retrieved from the National Coroners Information System (NCIS), the coronial case files of Australian jurisdictions, and the Crash Analysis System (CAS) of the New Zealand Transport Agency. Seventy seven (77) motorcycle fatalities involving a roadside barrier in Australia and New Zealand were examined. The fatalities usually involved a single vehicle crash and young men. The roadside barriers predominantly involved were steel W-beams, typically on a bend in the horizontal alignment of the road. A majority of fatalities occurred on a weekend, during daylight hours, on clear days with dry road surface conditions indicating predominantly recreational riding. Speeding and driving with a blood alcohol level higher than the legal limit contributed to a significant number of these fatalities.

Investigating the relative effects of sleep deprivation and time of day on fatigue and performance.

Time of day and the time since last sleep are acknowledged causes of fatigue, but comparatively little is known about how they interact. This study examines the relative effects of time of day and sleep deprivation on fatigue and performance. Two independent groups were exposed to 28 h of sleep deprivation beginning at 06:00 h for one group (n = 39) and at 00:00 h for the other (n = 22). By varying the start time for the two groups, but keeping constant the duration of sleep deprivation, the effects of variations in the time of day of testing could be examined. For the 06:00 h start group the longest period without sleep occurred close to the low point of the circadian rhythm. For the 00:00 h start group the circadian low point coincided with only two to six hours of sleep deprivation. Performance was evaluated two-hourly using eight computer-based tests and subjective fatigue ratings. The results showed a clear interaction effect. Both time of day and sleep deprivation affected performance but only in combination; neither had independent effects. These findings have implications for fatigue management.

Work characteristics associated with injury among light/short-haul transport drivers.

INTRODUCTION: This study aims to describe the hazard environment facing drivers of light freight vehicles and short-haul transport drivers and to examine the relationships between hazard exposure and injury. METHODS: Drivers (n=321) of rigid vehicles up to 12 tonnes Gross Vehicle Mass working within a 100 km radius of their base across the Australian state of New South Wales were surveyed regarding their experience of occupation-specific hazards and their experience of workplace injury in the past year. RESULTS: Principal components analysis identified four clusters of hazards corresponding to those associated with work organisation, vehicles, road and access, and interpersonal conflict. In logistic regression analysis, work organisation and vehicle-related hazards, explained unique variance in the experience of injury in the past year. However, frequent stress replaced work organisation when included as a predictor in the analysis. CONCLUSIONS: Drivers' most common safety concern (road and driving issues) reflected the frequency of their exposure to road and access hazards but did not parallel their injury experience. Examination of the hazards most strongly associated with injury suggest that industry risk management efforts should target work organisation and vehicle-related hazards, and particularly work practices that engender frequent stress among drivers.

Exploratory study of fatigue in light and short haul transport drivers in NSW, Australia.

This exploratory study sought to identify relationships between work characteristics and fatigue experiences among light and short haul road transport drivers. Surveys were distributed to drivers of light goods vehicles (< or =12 t gross vehicle mass) undertaking short haul work (within a 100 km radius of base) in seven geographical regions of NSW, Australia. The participating drivers (n=321) reported a range of freight tasks. They typically worked a 50-h, 5-day week primarily as day shifts, and spent just over half of their work time driving. Despite the predominance of regular, day work, 38% of participants experienced fatigue at least once a week while driving for work and 45% had nodded off while driving during the preceding 12 months. Stepwise logistic regression analysis revealed that longer daily work hours, higher subjective work demands, as measured by the NASA TLX workload scale, and the percentage of freight movements undertaken from customers to depots each explained unique variance in the frequency of fatigue experiences. The results of the study suggest that fatigue is an issue for some light and short haul road transport drivers and identifies work characteristics that should be investigated further.