Vision, functional and cognitive determinants of motor vehicle incidents in older drivers

Background: The proportion of older individuals in the driving population is predicted to increase in the next 50 years. This has important implications for driving safety as abilities which are important for safe driving, such as vision (which accounts for the majority of the sensory input required for driving), processing ability and cognition have been shown to decline with age. The current methods employed for screening older drivers upon re-licensure are also vision based. This study, which investigated social, behavioural and professional aspects involved with older drivers, aimed to determine: (i) if the current visual standards in place for testing upon re-licensure are effective in reducing the older driver fatality rate in Australia; (ii) if the recommended visual standards are actually implemented as part of the testing procedures by Australian optometrists; and (iii) if there are other non-standardised tests which may be better at predicting the on-road incident-risk (including near misses and minor incidents) in older drivers than those tests recommended in the standards. Methods: For the first phase of the study, state-based age- and gender-stratified numbers of older driver fatalities for 2000-2003 were obtained from the Australian Transportation Safety Bureau database. Poisson regression analyses of fatality rates were considered by renewal frequency and jurisdiction (as separate models), adjusting for possible confounding variables of age, gender and year. For the second phase, all practising optometrists in Australia were surveyed on the vision tests they conduct in consultations relating to driving and their knowledge of vision requirements for older drivers. Finally, for the third phase of the study to investigate determinants of on-road incident risk, a stratified random sample of 600 Brisbane residents aged 60 years and were selected and invited to participate using an introductory letter explaining the project requirements. In order to capture the number and type of road incidents which occurred for each participant over 12 months (including near misses and minor incidents), an important component of the prospective research study was the development and validation of a driving diary. The diary was a tool in which incidents that occurred could be logged at that time (or very close in time to which they occurred) and thus, in comparison with relying on participant memory over time, recall bias of incident occurrence was minimised. Association between all visual tests, cognition and scores obtained for non-standard functional tests with retrospective and prospective incident occurrence was investigated. Results: In the first phase,rivers aged 60-69 years had a 33% lower fatality risk (Rate Ratio [RR] = 0.75, 95% CI 0.32-1.77) in states with vision testing upon re-licensure compared with states with no vision testing upon re-licensure, however, because the CIs are wide, crossing 1.00, this result should be regarded with caution. However, overall fatality rates and fatality rates for those aged 70 years and older (RR=1.17, CI 0.64-2.13) did not differ between states with and without license renewal procedures, indicating no apparent benefit in vision testing legislation. For the second phase of the study, nearly all optometrists measured visual acuity (VA) as part of a vision assessment for re-licensing, however, 20% of optometrists did not perform any visual field (VF) testing and only 20% routinely performed automated VF on older drivers, despite the standards for licensing advocating automated VF as part of the vision standard. This demonstrates the need for more effective communication between the policy makers and those responsible for carrying out the standards. It may also indicate that the overall higher driver fatality rate in jurisdictions with vision testing requirements is resultant as the tests recommended by the standards are only partially being conducted by optometrists. Hence a standardised protocol for the screening of older drivers for re-licensure across the nation must be established. The opinions of Australian optometrists with regard to the responsibility of reporting older drivers who fail to meet the licensing standards highlighted the conflict between maintaining patient confidentiality or upholding public safety. Mandatory reporting requirements of those drivers who fail to reach the standards necessary for driving would minimise potential conflict between the patient and their practitioner, and help maintain patient trust and goodwill. The final phase of the PhD program investigated the efficacy of vision, functional and cognitive tests to discriminate between at-risk and safe older drivers. Nearly 80% of the participants experienced an incident of some form over the prospective 12 months, with the total incident rate being 4.65/10 000 km. Sixty-three percent reported having a near miss and 28% had a minor incident. The results from the prospective diary study indicate that the current vision screening tests (VA and VF) used for re-licensure do not accurately predict older drivers who are at increased odds of having an on-road incident. However, the variation in visual measurements of the cohort was narrow, also affecting the results seen with the visual functon questionnaires. Hence a larger cohort with greater variability should be considered for a future study. A slightly lower cognitive level (as measured with the Mini-Mental State Examination [MMSE]) did show an association with incident involvement as did slower reaction time (RT), however the Useful-Field-of-View (UFOV) provided the most compelling results of the study. Cut-off values of UFOV processing (>23.3ms), divided attention (>113ms), selective attention (>258ms) and overall score (moderate/ high/ very high risk) were effective in determining older drivers at increased odds of having any on-road incident and the occurrence of minor incidents. Discussion: The results have shown that for the 60-69 year age-group, there is a potential benefit in testing vision upon licence renewal. However, overall fatality rates and fatality rates for those aged 70 years and older indicated no benefit in vision testing legislation and suggests a need for inclusion of screening tests which better predict on-road incidents. Although VA is routinely performed by Australian optometrists on older drivers renewing their licence, VF is not. Therefore there is a need for a protocol to be developed and administered which would result in standardised methods conducted throughout the nation for the screening of older drivers upon re-licensure. Communication between the community, policy makers and those conducting the protocol should be maximised. By implementing a standardised screening protocol which incorporates a level of mandatory reporting by the practitioner, the ethical dilemma of breaching patient confidentiality would also be resolved. The tests which should be included in this screening protocol, however, cannot solely be ones which have been implemented in the past. In this investigation, RT, MMSE and UFOV were shown to be better determinants of on-road incidents in older drivers than VA and VF, however, as previously mentioned, there was a lack of variability in visual status within the cohort. Nevertheless, it is the recommendation from this investigation, that subject to appropriate sensitivity and specificity being demonstrated in the future using a cohort with wider variation in vision, functional performance and cognition, these tests of cognition and information processing should be added to the current protocol for the screening of older drivers which may be conducted at licensing centres across the nation.

In-vehicle driver distractions : characteristics underlying drivers' risk perceptions

Driver distraction continues to receive considerable research interest but the drivers��� perspective is less well documented. The current research focussed on identifying features that are salient to drivers in their risk perception judgements for 19 in-vehicle distractions. Both technological (e.g. mobile phones) and non technological (e.g. eating) distractions were considered. Analysis identified that males and females were rating 7 of the 19 distractions differently. The current paper presents the data for the female participants (n = 84). Multidimensional scaling analysis identified three main dimensions contributing to female drivers��� risk perception judgements. Qualitative characteristics such as the level of exposure to a distraction were identified as significant contributors to drivers��� risk perception as well as features inherent in the distractions such as distractions being related to communication. This exploratory work contributes to better understanding female drivers��� perceptions of risk associated with in-vehicle distractions. Understanding the drivers��� perspective can help guide the development of road safety messages and ultimately improve the impact of such messages.

Understanding the psychosocial factors influencing the risky behaviour of young drivers

Young people aged 17–24 years are at high risk of being killed in road crashes around the world. Road safety interventions consider some influences upon young driver behaviour; for example, imposing passenger restrictions on young novice drivers indirectly minimises the potential negative social influences of peers as passengers. To change young driver risky behaviour, the multitude of psychosocial influences upon its initiation and maintenance must be identified. A study questionnaire was developed to investigate the relationships between risky driving and Akers’ social learning theory, social identity theory, and thrill seeking variables. The questionnaire was completed by 165 participants (105 women,60 men) residing in south-east Queensland, Australia. The sociodemographic variables of age, gender, and exposure explained 19% of the variance in self-reported risky driving behaviour, whilst Akers’ social learning variables explained an additional 42%. Thrill seeking and social identity variables did not explain any significant additional variance. Significant predictors of risky driving included imitation of the driving behaviours of, and anticipated rewards and punishments administered by, parents and peers. Road safety policy that directly considers and incorporates these factors in their design, implementation, and enforcement of young driver road safety interventions should prove more efficacious than current approaches.

Exploring how parents and peers influence the behaviour of young drivers

Despite ongoing enhancements to graduated licensing systems, young drivers continue to have a high risk of being killed or injured in car crashes. This study investigated the influence of parents and peers on the risky behaviour of young drivers, utilising Akers’ social learning theory. The specific factors examined related to parent and peer norms perceived by the young driver, and the rewards and punishments anticipated by the young driver from their parents and peers. A questionnaire was completed by 165 young drivers. Regression analysis revealed that these factors explained 54% of the variance in risky driving. The strongest predictor was anticipated parent rewards, followed by peer norms, and anticipated peer rewards. Exploratory analyses however revealed the profile of predictors varied for male and female participants, and for self-reported offenders and non-offenders. The results highlight the role of psychosocial factors in the risky behaviour of young drivers and the need for road safety policies and programs to consider the influence of both parents and peers upon this behaviour.

Learning to drive with cognitive impairment : the experience of young ADHD diagnosed drivers and their parent supervisors

A subset of novice drivers exhibit executive function impairments which may adversely impact on the learn-to-drive period and subsequent driving experience, potentially explaining their overrepresentation in traffic offences and crashes. This paper presents the results of a qualitative analysis of a small series of in-depth semi-structured interviews undertaken individually with affected young drivers (n = 7) and each of their parent supervisors (n = 6). Young drivers were selected on the basis of their ADHD diagnosis, as a sample particularly affected by executive function impairments. Standardised rating scale measures confirmed the currency of the young drivers��� ADHD symptoms and executive function impairment. Results are discussed in terms of common experiences of the young affected drivers and those of their parents as supervising drivers of the learn-to-drive process and subsequent driving behaviour. Key themes included difficulties that were related to core executive function impairments symptomatic of ADHD. Themes also included common emotions that the young drivers associated with driving, with particular types of impact on their driving behaviour. Common strategies that were used by both the young driver and their parent during this learning process and their perceived effectiveness are also discussed. Those that were perceived to be most effective tended to focus on reducing the cognitive load for the young driver when introducing new information and skills.

Speeding in Australia and China : a comparison of the influence of legal sanctions and enforcement practices on car drivers

Despite increasingly sophisticated speed management strategies, speeding remains a significant contributing factor in 25% of Australia’s fatal crashes. Excessive speed is also a recognised contributor to road trauma in rapidly motorising countries such as China, where increases in vehicle ownership and new drivers, and a high proportion of vulnerable road users all contribute to a high road trauma rate. Speed choice is a voluntary behaviour. Therefore, driver perceptions are important to our understanding of the nature of speeding. This paper reports preliminary qualitative (focus groups) and quantitative (survey) investigations of the perceptions of drivers in Queensland and Beijing. Drivers��� definitions of speeding as well as their perceptions of the influence of legal factors on their reported speeds were explored. Survey participants were recruited from petrol stations (Queensland, n=833) and car washes (Beijing, n=299). Similarities were evident in justifications for exceeding speed limits across samples. Excessive speeds were not deemed as ‘speeding’ when drivers considered that they were safe and under their control, or when speed limits were seen as unreasonably low. This appears linked to perceptions of enforcement tolerances in some instances with higher perceived enforcement thresholds noted in China. Encouragingly, drivers in both countries reported a high perceived risk of apprehension if speeding. However, a substantial proportion of both samples also indicated perceptions of low certainty of receiving penalties when apprehended. Chinese drivers considered sanctions less severe than did Australian drivers. In addition, strategies to avoid detection and penalties were evident in both samples, with Chinese drivers reporting a broader range of avoidant techniques. Implications of the findings for future directions in speed management in both countries are discussed.

Enhancing road safety for young drivers : how Graduate Driver Licensing initiatives can complement "anti-hooning" legislation

Street racing and associated (hooning) behaviours have attracted increasing concern in recent years. While New Zealand and all Australian jurisdictions have introduced “antihooning” legislation and allocated significant police resources to managing the problem, there is limited evidence of the road safety implications of hooning. However, international and Australian data suggests that drivers charged with a hooning offence tend to be young males who are accompanied by one or more peers, and hooning-related crashes tend to occur at night. In this regard, there is considerable evidence that drivers under the age of 25 are over-represented in crash statistics, and are particularly vulnerable soon after obtaining a Provisional licence, when driving at night, and when carrying peer-aged passengers. The similarity between the nature of hooning offenders, offences and crashes, and road safety risks for young drivers in general, suggests that hooning is an issue that may be viewed as part of the broader young driver problem. Many jurisdictions have recently implemented a range of evidence-based strategies to address young driver road safety, and this paper will present Queensland crash and offence data to highlight the potential benefit of Graduated Driver Licensing initiatives, such as night driving restrictions and peer-aged passenger restrictions, to related road safety issues, including hooning. An understanding of potential flow-on effects is important for evaluations of anti-hooning legislation and Graduated Driver Licensing programs, and may have implications for future law enforcement resource allocation and policy development.

Mobile phone use while driving : an investigation of the beliefs influencing drivers��� hands-free and hand-held mobile phone use.

This study explored the psychological influences of hands-free and hand-held mobile phone use while driving. Participants were 796 Australian drivers aged 17 to 76 years who owned mobile phones. A cross-sectional survey assessed frequency of calling and text messaging while driving (overall, hands-free, hand-held) as well as drivers��� behavioural, normative, and control beliefs relating to mobile phone use while driving. Irrespective of handset type, 43% of drivers reported answering calls while driving on a daily basis, followed by making calls (36%), reading text messages (27%), and sending text messages (18%). In total, 63.9% of drivers did not own hands-free kits and, of the drivers that owned hand-free kits, 32% did not use it most or all of the time. Significant differences were found in the behavioural, normative, and control beliefs of frequent and infrequent users of both types of handset while driving. As expected, frequent users reported more advantages of, more approval from others for, and fewer barriers that would prevent them from, using either a hands-free or a hand-held mobile phone while driving than infrequent users. Campaigns to reduce mobile phone use while driving should attempt to minimise the perceived benefits of the behaviour and highlight the risks of this unsafe driving practice.

Drivers' and cyclists' experiences of sharing the road : incidents, attitudes and perceptions of visibility

This study explored the beliefs and attitudes of cyclists and drivers regarding cyclist visibility, use of visibility aids and crashes involving cyclists and motorists. Data are presented for 1460 participants (622 drivers and 838 cyclists) and demonstrate that there are high rates of cyclist–vehicle crashes, many of which were reported to be due to the driver not seeing the cyclist in time to avoid a collision. A divergence in attitudes was also apparent in terms of attribution of responsibility in cyclist–vehicle conflicts on the road. While the use of visibility aids was advocated by cyclists, this was not reflected in self-reported wearing patterns, and cyclists reported that the distance at which they would be first recognised by a driver was twice that estimated by the drivers. Collectively, these results suggest that interventions should target cyclists’ use of visibility aids, which is less than optimal in this population, as well as re-educating both groups regarding visibility issues.

The on-road difficulties of older drivers and their relationship with self-reported motor vehicle crashes

OBJECTIVES: To quantify the driving difficulties of older adults using a detailed assessment of driving performance and to link this with self-reported retrospective and prospective crashes. DESIGN: Prospective cohort study. SETTING: On-road driving assessment. PARTICIPANTS: Two hundred sixty-seven community-living adults aged 70 to 88 randomly recruited through the electoral roll. MEASUREMENTS: Performance on a standardized measure of driving performance. RESULTS: Lane positioning, approach, and blind spot monitoring were the most common error types, and errors occurred most frequently in situations involving merging and maneuvering. Drivers reporting more retrospective or prospective crashes made significantly more driving errors. Driver instructor interventions during self-navigation (where the instructor had to brake or take control of the steering to avoid an accident) were significantly associated with higher retrospective and prospective crashes; every instructor intervention almost doubled prospective crash risk. CONCLUSION: These findings suggest that on-road driving assessment provides useful information on older driver difficulties, with the self-directed component providing the most valuable information.

In-vehicle technology functional requirements for older drivers

Older drivers represent the fastest growing segment of the road user population. Cognitive and physiological capabilities diminishes with ages. The design of future in-vehicle interfaces have to take into account older drivers' needs and capabilities. Older drivers have different capabilities which impact on their driving patterns and subsequently on road crash patterns. New in-vehicle technology could improve safety, comfort and maintain elderly people's mobility for longer. Existing research has focused on the ergonomic and Human Machine Interface (HMI) aspects of in-vehicle technology to assist the elderly. However there is a lack of comprehensive research on identifying the most relevant technology and associated functionalities that could improve older drivers' road safety. To identify future research priorities for older drivers, this paper presents: (i) a review of age related functional impairments, (ii) a brief description of some key characteristics of older driver crashes and (iii) a conceptualisation of the most relevant technology interventions based on traffic psychology theory and crash data.

Drivers of adoption for successive generation of high-tech products

To understand the diffusion of high technology products such as PCs, digital cameras and DVD players it is necessary to consider the dynamics of successive generations of technology. From the consumer’s perspective, these technology changes may manifest themselves as either a new generation product substituting for the old (for instance digital cameras) or as multiple generations of a single product (for example PCs). To date, research has been confined to aggregate level sales models. These models consider the demand relationship between one generation of a product and a successor generation. However, they do not give insights into the disaggregate-level decisions by individual households – whether to adopt the newer generation, and if so, when. This paper makes two contributions. It is the first large scale empirical study to collect household data for successive generations of technologies in an effort to understand the drivers of adoption. Second, in contrast to traditional analysis in diffusion research that conceptualizes technology substitution as an “adoption of innovation” type process, we propose that from a consumer’s perspective, technology substitution combines elements of both adoption (adopting the new generation technology) and replacement (replacing generation I product with generation II). Key Propositions In some cases, successive generations are clear “substitutes” for the earlier generation (e.g. PCs Pentium I to II to III ). More commonly the new generation II technology is a “partial substitute” for existing generation I technology (e.g. DVD players and VCRs). Some consumers will purchase generation II products as substitutes for their generation I product, while other consumers will purchase generation II products as additional products to be used as well as their generation I product. We propose that substitute generation II purchases combine elements of both adoption and replacement, but additional generation II purchases are solely adoption-driven process. Moreover, drawing on adoption theory consumer innovativeness is the most important consumer characteristic for adoption timing of new products. Hence, we hypothesize consumer innovativeness to influence the timing of both additional and substitute generation II purchases but to have a stronger impact on additional generation II purchases. We further propose that substitute generation II purchases act partially as a replacement purchase for the generation I product. Thus, we hypothesize that households with older generation I products will make substitute generation II purchases earlier. Methods We employ Cox hazard modeling to study factors influencing the timing of a household’s adoption of generation II products. A separate hazard model is conducted for additional and substitute purchases. The age of the generation I product is calculated based on the most recent household purchase of that product. Control variables include size and income of household, age and education of decision-maker. Results and Implications Our preliminary results confirm both our hypotheses. Consumer innovativeness has a strong influence on both additional purchases and substitute purchases. Also consistent with our hypotheses, the age of the generation I product has a dramatic influence for substitute purchases of VCR/DVD players and a strong influence for PCs/notebooks. Yet, also as hypothesized, there was no influence on additional purchases. This implies that there is a clear distinction between additional and substitute purchases of generation II products, each with different drivers. For substitute purchases, product age is a key driver. Therefore marketers of high technology products can utilize data on generation I product age (e.g. from warranty or loyalty programs) to target customers who are more likely to make a purchase.

A comparison of the hazard perception ability of matched groups of healthy drivers aged 35 to 55, 65 to 74, and 75 to 84 years

We examined differences in response latencies obtained during a validated video-based hazard perception driving test between three healthy, community-dwelling groups: 22 mid-aged (35-55 years), 34 young-old (65-74 years), and 23 old-old (75-84 years) current drivers, matched for gender, education level, and vocabulary. We found no significant difference in performance between mid-aged and young-old groups, but the old-old group was significantly slower than the other two groups. The differences between the old-old group and the other groups combined were independently mediated by useful field of view (UFOV), contrast sensitivity, and simple reaction time measures. Given that hazard perception latency has been linked with increased crash risk, these results are consistent with the idea that increased crash risk in older adults could be a function of poorer hazard perception, though this decline does not appear to manifest until age 75+ in healthy drivers.

Service staff attitudes, organisational practices and performance drivers

We provide conceptual and empirical insights elucidating how organizational practices influence service staff attitudes and behaviors and how the latter set affects organizational performance drivers. Our analyses suggest that service organizations can enhance their performance by putting in place strategies and practices that strengthen the service-oriented behaviors of their employees and reduce their intentions to leave the organization. Improved performance is accomplished through both the delivery of high quality services (enhancing organizational effectiveness) and the maintenance of frontline staff(increasing organizational efficiency). Specifically, service-oriented business strategies in the form of organizational-level service orientation and practices in the form of training directly influence the manifest service-oriented behaviors of staff. Training also indirectly affects the intention of frontline staff to leave the organization; it increases job satisfaction, which, in turn has an impact on affective commitment. Both affective and instrumental commitment were hypothesized to reduce the intentions of frontline staff to leave the organization, however only affective commitment had a significant effect.

Mobility and safety are conflicting goals for transport policy makers when making decisions about graduated driver licensing

Policy decisions are frequently influenced by more than research results alone. This review examines one road safety countermeasure, graduated driver licensing, in three jurisdictions and identifies how the conflict between mobility and safety goals can influence policy decisions relating to this countermeasure. Evaluations from around the world of graduated driver licensing have demonstrated clear reductions in crashes for young drivers. However, the introduction of this countermeasure may be affected, both positively and negatively, by the conflict some policy makers experience between ensuring individuals remain both mobile and safe as drivers. This review highlights how this conflict in policy decision making can serve to either facilitate or hinder the introduction of graduated driver licensing systems. However, policy makers whose focus on mobility is too strong when compared with safety may be mistaken, with evidence suggesting that after a graduated driver licensing system is introduced young drivers adapt their behaviour to the new system and remain mobile. As a result, policy makers should consciously acknowledge the conflict between mobility and safety and consider an appropriate balance in order to introduce these systems. Improvements to the licensing system can then be made in an incremental manner as the balance between these two priorities change. Policy makers can achieve an appropriate balance by using empirical evidence as a basis for their decisions.