Judith Lynne Charlton

Riding through red lights: The rate, characteristics and risk factors of non-compliant urban commuter cyclists

This study determined the rate and associated factors of red light infringement among urban commuter cyclists. A cross-sectional observational study was conducted using a covert video camera to record cyclists at 10 sites across metropolitan Melbourne, Australia from October 2008 to April 2009. In total, 4225 cyclists faced a red light and 6.9% were non-compliant. The main predictive factor for infringement was direction of travel, cyclists turning left (traffic travels on the left-side in Australia) had 28.3 times the relative odds of infringement compared to cyclists who continued straight through the intersection. Presence of other road users had a deterrent effect with the odds of infringement lower when a vehicle travelling in the same direction was present (OR=0.39, 95% CI 0.28-0.53) or when other cyclists were present (OR=0.26, 95% CI 0.19-0.36). Findings suggest that some cyclists do not perceive turning left against a red signal to be unsafe and the opportunity to ride through the red light during low cross traffic times influences the likelihood of infringement.

Neuropsychological Function and Driving Ability in People with Parkinson's Disease

In this study the association between cognitive symptoms of PD and driving performance was investigated by examining the correlation between neuropsychological test performance and driving simulator behavior. Eighteen participants with PD and 18 healthy participants in a matched comparison group completed a range of neuropsychological measures. These data were correlated with driving simulator performance results from an earlier study. Significant correlations were found between several measures of neuropsychological test performance and driving behavior in participants with PD. In contrast, few significant correlations were obtained in the comparison group. Results suggest that executive difficulties in people with PD such as working memory, planning and set shifting are associated with reduced tactical level driving performance such as speed adaptation and complex curve navigation. Impaired information processing, visual attention and visual perception in people with PD appears associated with reduced operational level driving performance, such as reacting to road obstacles and maintaining constant lane position. Few correlations were found between measures of physical mobility and psychomotor speed with driving measures. Overall, this study highlights the important role of cognitive function in driving performance within the PD population. Comprehensive assessment of cognitive function should be included when assessing driving competency in people with PD.

Driving ability in Parkinson's disease: Current status of research

Guidelines for assessing fitness to drive in individuals with neurodegenerative disorders, such as Parkinsons disease (PD), are subjective. It is therefore timely to review the current status of the literature not only for health professionals who are required to assess fitness to drive, but also for the development of future research directions. This review, in the context of PD, outlines the complex changes in driving behaviours, motor vehicle crash rates, driving simulator and on-road driving ability assessments, the relationship between disease severity, duration, medication dose and driving performance, the relationship between driving and neuropsychological test performance, and the effect of dopaminergic medications on driving. While it provides a current overview of the ongoing research, more comprehensive research is required for the full and proper development of policies and guidelines for assessing fitness to drive in PD.

Impact of internal versus external cueing on driving performance in people with Parkinson's disease.

Numerous aspects of driving performance seem compromised in people with Parkinsons disease (PD). Measures of cognitive impairment consistently correlate with poor driving simulator performance in this population; however, the effects of specific cognitive difficulties on discrete aspects of driving behavior have not been investigated thoroughly. Previous studies have demonstrated that people with PD exhibit difficulties internally cueing cognitive processes. This study examined the impact of impaired internal cueing on specific driving behaviors. A simulator measured the driving behavior of 18 current drivers in the mild‐to‐moderate stages of PD and 18 matched controls. Participants navigated through different driving conditions where the opportunity to use internal and external cues was manipulated. People with PD exhibited difficulties using internal cues to regulate driving behavior around traffic signals and curves. Instead of using internal cues, participants with PD were more reliant on external cues to regulate driving behavior. They were also less able to adapt their driving behavior to suit driving conditions. Because all participants with PD were current drivers in the mild‐to‐moderate stages of the disease, findings challenge the widely‐held assumption that cognitive difficulties only impact on driving performance in the moderate‐to‐severe stages of PD.

Investigating driving behaviour of older drivers with mild cognitive impairment using a portable driving simulator

While there is a large body of research indicating that individuals with moderate to severe dementia are unfit to drive, relatively little is known about the driving performance of older drivers with mild cognitive impairment (MCI). The aim of the current study was to examine the driving performance of older drivers with MCI on approach to intersections, and to investigate how their healthy counterparts perform on the same driving tasks using a portable driving simulator. Fourteen drivers with MCI and 14 age-matched healthy older drivers (aged 65-87 years) completed a 10-min simulator drive in an urban environment. The simulator drive consisted of stop-sign controlled and signal-controlled intersections. Drivers were required to stop at the stop-sign controlled intersections and to decide whether or not to proceed through a critical light change at the signal-controlled intersections. The specific performance measures included; approach speed, number of brake applications on approach to the intersection (either excessive or minimal), failure to comply with stop signs, and slower braking response times on approach to a critical light change. MCI patients in our sample performed more poorly than controls across a number of variables. However, because the trends failed to reach statistical significance it will be important to replicate the study using a larger sample to qualify whether the results can be generalised to the broader population.

Factors affecting self-regulatory driving practices among older adults

Objective: The primary objective of this study was to better understand how self-regulatory driving practices at multiple levels of driver decision making are influenced by various factors. Specifically, the study investigated patterns of tactical and strategic self-regulation among a sample of 246 Australian older drivers. Of special interest was the relative influence of several variables on the adoption of self-regulation, including self-perceptions of health, functioning, and abilities for safe driving and driving confidence and comfort. Methods: The research was carried out at the Monash University Accident Research Centre, as part of its Ozcandrive study, a partnership with the Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive), and in conjunction with the University of Michigan Transportation Research Institute (UMTRI). Candrive/Ozcandrive represents the first study to follow a large group of older drivers over several years and collect comprehensive self-reported and objectively derived data on health, functioning, and driving. This study used a subset of data from the Candrive/Ozcandrive study. Upon enrolling in the study, participants underwent a comprehensive clinical assessment during which data on visual, cognitive, and psychomotor functioning were collected. Approximately 4 months after study enrollment, participants completed the Advanced Driving Decisions and Patterns of Travel (ADDAPT) questionnaire, a computer-based self-regulation instrument developed and pilot-tested at UMTRI. Results: Self-regulation among older adults was found to be a multidimensional concept. Rates of self-regulation were tied closely to specific driving situations, as well as level of decision making. In addition, self-regulatory practices at the strategic and tactical levels of decision making were influenced by different sets of factors. Conclusions: Continuing efforts to better understand the self-regulatory practices of older drivers at multiple levels of driver performance and decision making should provide important insights into how the transition from driving to nondriving can be better managed to balance the interdependent needs of public safety and personal mobility.

Effect of a Concurrent Task on Driving Performance in People with Parkinson's Disease

Numerous studies previously have reported reduced driving performance in people with Parkinsons disease (PD). Few studies to date, however, have examined how specific cognitive difficulties associated with PD impact on specific aspects of driving performance in this population. In this study, the impact of a concurrent task on driving performance was examined. A simulator was used to measure the driving behavior of 18 current drivers with PD and 18 matched controls. The presence of a concurrent task was manipulated between conditions. Results showed that, although groups were similarly affected by the concurrent task on most driving measures, participants with PD were disproportionately affected on operational level driving behavior. It also appears that participants with PD sacrificed concurrent task performance to maintain driving performance. These results further support the hypothesis that cognitive difficulties associated with PD compromise driving performance in this population, even in the mild to moderate stages of the disease.

Driving avoidance by older adults: Is it always self-regulation?

Self-regulation shows promise as a means by which older adults can continue to drive at some level without having to stop altogether. Self-regulation is generally described as the process of modifying or adjusting ones driving patterns by driving less or intentionally avoiding driving situations considered to be challenging, typically in response to an awareness that driving skills have declined. However, most studies asking older adults whether they avoid certain driving situations or have reduced the amount of driving they do under certain circumstances have not delved deeper into the motivations for such avoidance or driving reduction. There are many reasons for modifying driving that have nothing to do with self-regulation, such as no longer needing to take trips at certain times of day because of changes in preferences or lifestyles. The purpose of this study was to examine self-regulatory practices among older adults at multiple levels of driver performance and decision making, taking into account the specific motivations for avoiding particular driving situations or engaging in other driving practices. Study participants completed a computer-based questionnaire on driving self-regulation. Results suggest that self-regulation is a complex process that cannot be defined simply by the reported driving modifications made by drivers. Understanding the motivations for these behaviors is necessary and the study showed that they are varied and differ considerably across driving situations. Reasons for driving avoidance or other practices were often more closely related to lifestyle or preferences than to self-regulation. Based on these findings, three distinct groups were identified with regard to whether and for what reasons participants modified their driving.

Child restraint system misuse and/or inappropriate use in Australia

Objective: Motor vehicle crashes are one of the leading causes of child death and acquired disability. Child restraint systems (CRS) for vehicles are designed to provide specialized protection for child occupants in the event of a crash. However, the effectiveness of a CRS is critically dependent on: correct installation of the CRS in the vehicle, the correct harnessing of the child in the CRS, and use of an appropriate CRS. The current study aimed to investigate the incidence misuse and/or inappropriate use of CRS through a CRS inspection program in the Australian states of New South Wales (NSW), Victoria (VIC), Queensland (QLD), South Australia (SA), Western Australia (WA), and Tasmania (TAS). Methods: Participants were recruited through an advertisement for free CRS inspections displayed at childcare centers, kindergartens, community centers, hospitals, and child expos. At each inspection, the CRS fitting specialist inspected and reported to the owner of the CRS on the installation of the child restraint(s) and/or system(s) and any fitting faults and/or concerns with the fitting and/or use if the child restraint(s) and or system(s). Results: The following results are based on the inspection of 1386 vehicles, in which there were 1995 restraints. Of all the restraints inspected, the majority (79%) were reported as having at least one instance of misuse. The most common forms of misuse included harness strap errors such as the straps being adjusted, faulty, twisted, and/or incorrectly positioned (38%); seat belt errors such as the seatbelt being incorrectly routed, twisted, and/or incorrectly adjusted (32%); missing or incorrect fitting of gated buckle/locking clip (23%); the need for a missing sash guide (8%); tether errors such as the tether being incorrectly routed and/or adjusted (7%); inappropriate use of a CRS for the size of the child (6%); anchor errors such as the anchor was fitted incorrectly or not the correct type (5%); and the H Harness 1 being used incorrectly (5%). In addition, there were significant differences across restraint types in terms of the proportion of restraints with CRS misuse or fitment errors, χ2 (2) = 51.42, p < 0.001. The rate of misuse was highest for the forward-facing CRS (88%), compared to infant seats (67%) and booster seats or cushions (63%). 1 An H harness is an additional device that is designed for use with or without booster seats for children weighing up to 32 kg. The harness is attached to the vehicle at the same point as a CRS top tether, with the lap belt of the vehicle threaded through the harness. Discussion: The results show that CRS misuse and fitment errors are widespread in Australia. Based on the findings of this study, it is recommended that educational and awareness materials and programs that provide information on the safety benefits associated with correct CRS use (as well as the injury risk associated with CRS misuse) be developed for both parents and children.

General health status and functional disability following injury in traffic crashes

Objective. With increasing rates of survival associated with traffic crashes, a shift to understand the consequences of injury has risen to prominence. This prospective cohort study set out to examine general health status and functional disability at 2 months and 6–8 months post-crash. Methods. Participants were otherwise healthy adults aged 18–59 years admitted to hospitals, excluding those with moderate–severe head injury and spinal cord injury. Sixty-two adults completed interviews prior to discharge and at 2 months and 8 months post-discharge. Results. By 8 months post-crash, 89 percent had resumed employment and or study, two thirds rated the resolution of their medical problems to be excellent (14.5 percent) or good (53 percent), and 82 percent were considered to be fully self-sufficient with respect to activities of daily living. Despite this, results from the SF-36 indicated significant reductions in health status at 2 and 8 months post-crash relative to pre-crash health, with domain scores up to 26 percent lower than pre-crash scores, while assessment of activities of daily living indicated residual functional disability at both follow-up times. Self-reported pain was higher for both males and females at both follow-up times compared with pre-crash self-reported pain. Conclusion. This study demonstrated significant, ongoing loss of health-related quality of life and impairment associated with injuries sustained in road crashes, highlighting the need for continuing care post-discharge to facilitate a rapid return to optimal health.