Casr report series

5.1Gaps in research

One issue with regard to training that was raised in US research (Brock, McFann, Inderbitzen, and Bergoffen, 2007) was the use of experienced drivers as trainers with little regard to whether or not such individuals had the skills and attributes required of a good trainer.

Canadian studies of HV drivers have highlighted the importance of a minimum standard of literacy and numeracy skills for heavy vehicle drivers. This evidence indicates that training in literacy and numeracy may be required in addition to training drivers in the operation of heavy vehicles. The Australian HV industry may benefit from similar research regarding the effects of basic literacy and numeracy on HV safety.

The ecodrive training program has been demonstrated to effectively improve drivers’ performance with regard to fuel economy and gear and braking inputs. A large scale evaluation of this driving method with regard to the safety benefits of ecodrive may be warranted given that it may offer a simple and cost-effective (it requires no specialised equipment and the only cost is associated with the training itself) solution for improving road safety.

Very little was found with regard to the health of heavy vehicle drivers and its influence on fitness to drive. Given that research indicates truck driving is associated with a number of health issues, including obesity, cardiovascular disease, diabetes, and sleep apnoea research into this area could provide valuable insight into the links between driver health and crashes and identify potential strategies to manage these risks.

Much of the research with regard to the impact of human factors on HV road safety focuses largely on the negative. That is, data usually relates to crash-involved drivers and the focus of research tends to be factors that cause or contribute to crash risk. A line of research that is largely overlooked involves the identification of factors that contribute to higher levels of safety, that is, what makes the safest drivers the safest drivers? This line of research may be able to inform driver training however, an inherent difficulty in such an approach lies in identifying safe drivers, a task inherently more difficult than identifying drivers involved in a crash.

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  There are inconsistencies in the evidence as to whether solo truck drivers are at greater risk of crash due to fatigue compared to team drivers.
  
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  The effects of truck driving experience, age, and other individual differences are not consistent among studies. Further research should be aimed at clarifying these relationships in order to determine populations of truck drivers who may be at greater risk of fatigue-related crashes. Research into truck driver fatigue education and potential interventions could then be targeted at those at greatest risk of fatigue-related crashes.
  
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  The effects and time-course of chronic sleep restriction needs further investigation, including assessment of differences in performance and recovery compared to the effects of total sleep deprivation. These findings are likely to be more relevant to the effects of fatigue in truck drivers and may better inform drivers and the industry on the extent of rest required between shifts, particularly if these shifts are likely to restrict sleep over a number of days.
  
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  Research investigating actions which may influence individual circadian rhythms and chronotypes may be of use in order to combat the deleterious effects of time of day and circadian phase on driving performance and fatigue. In particular, research regarding the impact of irregular shifts or driving hours on fatigue is needed.
  
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  Sleep disorders and medical conditions causing fatigue, as well as related medications and treatments requires further research. The benefit of this research in the trucking industry will be further discussed in the section related to sleep apnoea.
  
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  As shown, there were a number of factors likely to influence the development of fatigue, the relative importance of these factors compared to each other, in differing situations, and in interaction with each other should be evaluated. Not only may additional important risk factors for sleep related crashes be found, but factors which can be easily manipulated in comparison to other more difficult factors may be targeted to potentially create protective effects. Knowledge of the influence of additional fatigue factors could also be incorporated in efforts to predict fatigue risk or detect fatigue.
  
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  Further research into the benefit of different countermeasures in combating fatigue would be useful in order to better inform truck drivers of effective methods and the duration of these beneficial effects. Activities aimed at fatigue reduction that may distract the driver from the primary task of driving should also be extensively evaluated, taking the potential negative effects of distraction into account.
  
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  The evaluation of effectiveness and development of fatigue detection technologies requires further research. Evaluations should be based on a range of criteria (from reliability, validity and sensitivity, to the time and cost of the device, the ability to overcome individual differences, the flexibility of the system in different conditions, risk of data loss, and the intrusiveness of the device) and should occur in both naturalistic and laboratory settings as both have differing advantages and disadvantages.
  
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  Fatigue prediction models require further scientific validation due to their apparent divergence from theory. These technologies may be particularly helpful in the trucking industry by informing managers of fatigue risk prior to drivers starting a shift.
  
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  Further research should be aimed at determining the effect of different warning systems on driver behaviour.
  
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  Further research investigating the criteria required to determine fatigue post-crash would be beneficial. Fatigue is particularly difficult to determine post-crash compared to other more obvious causes. A model and robust set of criteria for determining fatigue post-crash, particularly in crashes where the driver cannot be interviewed (such as in fatal crashes) will improve the ability for researchers to determine the prevalence and importance of fatigue. A figure which is likely to be underestimated due to difficulties in identification post-crash. Additionally, there may be fatal crashes of a particular type which are fatigue related which are often not recognised. Recognising these crashes may provide more targets for interventions as well as provide greater understanding of fatigue effects in real world conditions. Fatigue detection technologies could be beneficial in determining the relationship between fatigue and crashes when other factors are present (such as speed), however these need to be further developed before they can be relied on for this cause.
  
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  Further research into lifestyle factors that can lead to risk of sleep apnoea. Interventions targeting lifestyle and healthy Body Mass Indexes (BMI) may reduce sleep apnoea in the trucking population and therefore reduce risk of crash due to sleep apnoea. A number of additional health benefits are also associated with healthy BMI.
  
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  Further research into therapies and treatments (including medications) for conditions (such as sleep apnoea) that can lead to fatigue related crashes would be beneficial. This would ideally include a cost-benefit analysis of the treatments as well as potential deleterious side effects.
  
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  The relationship between sleep apnoea and other fatigue-related risk factors should be investigated in future research, particularly as these other factors are often not evaluated in the sleep apnoea research. Determining these potential interactions will enable better understanding of the effects of sleep apnoea, and may highlight areas of potential preventative action.
  
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  Disorders and medical conditions that lead to fatigue, other than sleep apnoea, have received relatively little attention in the scientific literature in terms of how they relate to crash risk. The prevalence of these conditions in the trucking industry as well as the risks associated with these conditions and potential treatments should be further evaluated in future research.
  
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  Finally, collaboration between researchers from various disciplines in order to come to an improved agreement on the definition of fatigue, and/or definitions of it’s subtypes, will be greatly beneficial to furthering the understanding of fatigue and it’s effects.
  

There is scope for improving the management of substance use within the HV industry. Any effort to do so should be evidence based and guided by best practice. Research may be required to facilitate this improved management should:

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  Identify the prevalence of substance use and the driver (i.e., individual) characteristics associated with substance use.
  
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  Research is needed to determine the extent of heavy vehicle driver’s knowledge of substance use and the effects these have, particularly with regard to driving performance in order to determine the most suitable intervention for reducing the impact of substance use on heavy vehicle road safety. This research may also address the feasibility of education programs or the development of a substance use knowledge network for the heavy vehicle industry.
  

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  Observational studies of HV occupant seat belt use would provide a more accurate indication of seat belt use rates.
  
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  One strategy that has had some success in improving restraint use in passenger vehicles has been the seat belt reminder, a passive technology that emits a warning light, noise, or both to remind occupants to wear a seat belt. Research should seek to address the effectiveness of such devices in heavy vehicles.
  
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  A similar approach, the seat belt interlock, prevents the operation of the vehicle when the seat belt is not engaged. Research should seek to address the effectiveness of such devices in heavy vehicles.
  
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  Similar strains of research may address the use of other compliance options such as the use of on-board monitoring devices and telematics.