Driving Task: How Older Drivers' On-Road Driving Performance Relates to Abilities, Perceptions, and Restrictions.

This study examined a cohort of 227 older drivers and investigated the relationship between performance on the electronic Driver Observation Schedule (eDOS) driving task and: (1) driver characteristics; (2) functional abilities; (3) perceptions of driving comfort and abilities; and (4) self-reported driving restrictions. Participants (male: 70%; age: M = 81.53 years, SD = 3.37 years) completed a series of functional ability measures and scales on perceived driving comfort, abilities, and driving restrictions from the Year 2 Candrive/Ozcandrive assessment protocol, along with an eDOS driving task. Observations of participants' driving behaviours during the driving task were recorded for intersection negotiation, lane-changing, merging, low-speed maneuvers, and maneuver-free driving. eDOS driving task scores were high (M = 94.74; SD = 5.70) and significantly related to participants' perceived driving abilities, reported frequency of driving in challenging situations, and number of driving restrictions. Future analyses will explore potential changes in driving task scores over time.

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.

Tactical, strategic, and life-goal self-regulation of driving by older adults: development and testing of a questionnaire.

INTRODUCTION: Appropriate self-regulation of driving - that is, adjusting one's driving patterns by driving less or avoiding specific situations considered challenging - shows promise as a strategy for extending safe driving. However, results on the extent of self-regulatory practices among older drivers vary considerably across studies. METHOD: The purpose of this study was to develop and test a questionnaire to measure self-regulation at multiple levels of driver performance and decision making, using a sample of older drivers comprised of individuals with clinically-determined functional impairments, as well as older adults recruited from the general population. RESULTS: Results suggest that the questionnaire is a user-friendly instrument for gathering information from older adults about their self-regulatory practices which has good construct validity. Feedback on the questionnaire was positive. Construct validity of the questionnaire was assessed by comparing the recruitment populations along various dimensions on which they might be expected to differ (e.g., self-rated health and functioning, abilities for safe driving, and feelings of driving comfort/safety) and looking for correlations between variables that one would reasonably expect to be correlated. CONCLUSIONS: Overall, participants rated their general health and functioning, and abilities for safe driving quite highly. However, participants from the clinic population rated themselves lower than participants from the general population on several abilities including seeing clearly during the day and night, remembering things, and processing information. While participants reported high levels of driving comfort and safety for most driving situations, the clinic population reported lower levels of comfort and safety for every driving circumstance except driving alone. High correlations were found between comfort and safety and the absolute mean scores were nearly identical for each driving circumstance. Finally, the clinic population was more likely to report trying to avoid driving at night, in unfamiliar areas, and on the expressway, as well as chatting with passengers. IMPACT ON THE INDUSTRY: Results of this pilot work provide insights into the self-regulatory driving process that could eventually inform efforts to extend safe mobility among older adults.

Reprint of "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 one's 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.

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 one's 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.

Protocol for Candrive II/Ozcandrive, a multicentre prospective older driver cohort study.

The Candrive II/Ozcandrive study, a multicentre prospective cohort study examining the predictive validity of tools for assessing fitness to drive, aims to develop an in-office screening tool that will help clinicians identify older drivers who may be unsafe to drive. This paper describes the study protocol. We are following a cohort of drivers aged ≥70 years for up to 4 years. Starting in 2009, 928 participants have been recruited in seven cities in four Canadian provinces, as well as 302 participants in two sites in Melbourne, Australia and Wellington, New Zealand. Participants underwent a comprehensive assessment at baseline and repeat the assessment yearly thereafter, as well as a brief follow-up assessment at 4 and 8 months each year. A recording device is installed in participants' vehicles to assess driving patterns, and driving records are obtained from licensing authorities to determine the outcomes: at-fault crashes per kilometre driven and violations. To date, the protocol has been generally well adhered to, with 1230 participants, and barriers and challenges are being addressed, as necessary. The Candrive II/Ozcandrive study is unique owing to its size, duration, partnerships with Canadian, Australian and New Zealand stakeholders, and international research collaboration.

Findings from the Candrive/Ozcandrive study: Low mileage older drivers, crash risk and reduced fitness to drive.

Previous research has found that only older drivers with low annual driving mileages had a heightened crash risk relative to other age groups. These drivers tend to drive mainly in urban areas, where the prevalence of complex traffic situations increases crash risk. However it might also be that some drivers may have reduced their driving due to perceived or actual declines in driving fitness. This paper uses Canadian and Australian data from the Candrive/Ozcandrive older driver study to investigate the association between annual driving distances and a set of driving-related factors, including fitness to drive. All drivers in the Candrive/Ozcandrive older driver cohort study were allocated to one of three groups according to their self-reported annual driving distances: <5001km; >5000 and <15,000km; and 15,000km or greater. Relationships between these driving-distance categories and: (a) self-reported crash data; (b) various Year 1 'fitness to drive' performance measures; and (c) self-perceptions of driving ability and of comfort while driving, were determined. Results confirmed the previously reported association between low mileage and heightened crash risk. Further, low mileage drivers performed relatively poorly on a wide range of performance measures, perceived their own driving ability as lower, and reported lower comfort levels when driving in challenging situations, compared to the higher mileage drivers. In most instances, these differences were statistically significant. The paper provides further evidence that the so-called 'older driver problem' is most pertinent to low mileage drivers, and that this is due in part to low mileage drivers tending to have reduced fitness to drive. This higher risk group represented a fairly small proportion of the sample in this study.

The Relationship between Older Drivers' Performance on the Driving Observation Schedule (eDOS) and Cognitive Performance.

RESEARCH QUESTION/OBJECTIVE: The Driving Observation Schedule (eDOS) was developed for use in the Candrive/Ozcandrive five-year prospective study of older drivers to observe the driving behavior of older drivers and monitor changes in driving behaviors over time. The aim of this study is to describe participants' driving performance during the eDOS driving task and investigate the association between driving performance and cognitive measures. METHODS: A subset of Ozcandrive participants (n = 144, 104 male [72%], 40 female [28%], Mean age = 81.49 years, SD = 3.58 years, Range: 76 - 96 years) completed the eDOS driving task. Participants drove to their selected destinations (up to 4 locations), with observations of driving behaviors (both inappropriate and appropriate) recorded for specific driving maneuvers: intersection negotiation, lane-changing, merging, low speed maneuvers and maneuver-free driving. Driving behaviors (e.g. signalling, speed regulation, gap acceptance, lane position, 'critical errors') were scored by a trained observer and participants received an overall eDOS driving task score (Maximum = 100 points). Participants also completed a series of cognitive assessments as part of the Year 2 Candrive/Ozcandrive assessment protocols. RESULTS: The overall eDOS driving task score was very high (M = 95.77; SD = 5.15; Range = 65.63 - 100). Detailed analyses of participants' driving behavior revealed a high level of appropriate driving behavior (96%, n = 5,935 maneuvers), with few errors (4%, n = 252 maneuvers). While most participants' performance on the cognitive assessments was high, some scores were below the criteria for cogntive impairment (BIC) according to conventional benchmarks: (MoCA: M = 26.56, SD = 2.12, Range = 19 - 30, % BIC = 28%; MMSE: M = 29.10, SD = 1.01, Range = 26-30, %BIC = 0%; Trails B: M = 111.66, SD = 43.53, Range = 50 - 301, %BIC = 6%). There was no significant relationship observed between participants' overall eDOS driving task scores and age (r (144) = -0.17, p > 0.05), and performance on various cognitive assessments including: MoCA (r (144) = 0.07, p > 0.1), MMSE (r (144) = 0.03, p > 0.5), Trail Making Test B (r (144) = 0.09, p > 0.1). IMPLICATIONS: Preliminary analyses of the eDOS driving task revealed a high level of appropriate driving behavior among Ozcandrive older drivers. Despite some participants' cognitive performance suggesting impairment, participants' overall eDOS driving task scores were not significantly related to cognitive performance. This finding is consistent with previous research suggesting some older drivers are able to compensate well for age-related cognitive impairment.

Older drivers, crashes and injuries.

OBJECTIVE: This article aimed to identify the main features of older driver casualty crashes, including detailed descriptions of injury outcomes. METHODS: Data were obtained from the Transport Accident Commission insurance claims database for 2 groups of drivers: aged 41 to 55 years (middle-aged drivers) and aged 65 years and older (older drivers). RESULTS: In terms of crash circumstances, the majority of crashes involved a collision with another vehicle (70.0% of middle-aged drivers and 68.7% of older drivers). The 2 main maneuvers at the time of crash were driving straight ahead (44.6% of middle-aged drivers and 42.8% of older drivers) and turning right (equivalent of left turn in North America; 15.2% of middle-aged drivers and 17.6% of older drivers). In terms of injury outcomes, older drivers sustained a significantly higher proportion of injuries to the thorax (30.9% compared to 18.5% of middle-aged drivers). Conversely, a significantly higher proportion of middle-aged drivers sustained some form of injury to the neck (30.6% compared to 12.1% of older drivers). CONCLUSION: These findings highlight the situations that are particularly risky for older drivers and provide important insights for developing solutions to reduce older driver crash and injury risk.

Licence restrictions as an under-used strategy in managing older driver safety.

While many older drivers remain unimpaired or otherwise effectively compensate for functional deficits, a minority are currently faced with two main options: either continue to drive with arguably an unacceptable crash risk; or cease driving, perhaps at the instigation of licensing authorities. Licence restrictions represent a possible third option for some older drivers, by better managing crash risk while still allowing acceptable levels of mobility. The present study has explored licence restrictions as applied to Victorian older drivers over a ten-year period. It has identified the types of restrictions and their extent of use in recent years, plus indications of potential safety benefits that may result from restricted licencing practices. Less than 10% of the older driver cohort had a licence restriction and in around 95% of instances, the restriction related to the need to wear corrective lenses; these numbers precluded a conclusive evaluation of safety benefits. However, two important findings emerged. First, the imposition of a licence restriction was usually associated with a reduction in absolute crash rates. Second, three restrictions were identified that most readily form the basis of a graduated driving reduction program.

Do age-based mandatory assessments reduce older drivers' risk to other road users?

To assess whether different licensing policies were associated with different fatality levels, the fatality outcomes of older drivers in Victoria and New South Wales (NSW) were compared. In Victoria, there is no age-based assessment required for re-licensing, while in NSW, drivers aged 80 years and older are required to provide annual medical certificates and from age 85, are required to pass on-road driving tests. Fatality rates associated with older drivers in each jurisdiction were calculated for the main categories of road users on two bases: per number of target drivers and per number of licensed drivers. When fatality outcomes were considered relative to the number of 80-plus year-olds in the Victorian and NSW populations, there was no significant difference in the overall fatality rate between the two groups. Similarly, there was no significant difference between the two groups in terms of the fatality rate for all other road users and for road users not in the older drivers' vehicles. When fatality outcomes were considered relative to the number of 80-plus year-old licensed drivers in either Victoria or NSW, Victorian older drivers were associated with a lower overall fatality rate and the difference was marginally statistically significant. Victorian older drivers were also associated significantly lower fatality rate for road users not in the older drivers' vehicles. Victorian older drivers represented a statistically significant higher risk in one major regard: to their passengers. Victorian drivers aged 80 years and older had between two and three times higher passenger fatality rates compared to NSW drivers. However it was also found that Victorian older drivers had a significantly higher passenger occupancy rate than their NSW equivalents. Once Victorian and NSW older drivers' different passenger occupancy rates were controlled for, there were no statistically significant differences across the two jurisdictions. These findings collectively suggested that age-based mandatory assessment programs do not have demonstrable safety benefits, in terms of either total fatalities or other road user fatalities--thereby broadly confirming the findings from previous research based on older driver crash involvement.

In defence of the 'low-mileage bias'.

There has been a long-recognised association between extent of driving and crash involvement: the lower the annual mileage driven, the higher the per-distance crash rate. Because older drivers generally drive less distance per year than others, this association has been used to explain much of their apparent over-involvement in crashes. Several studies from different countries around the world have demonstrated this 'low-mileage bias' and the relative safety of older drivers. However all studies have relied upon self-reported crash involvement and driving activity. Staplin et al. [Staplin, L., Gish, K., Joyce, J., 2008. 'Low mileage bias' and related policy implications-a cautionary note. Accident Analysis and Prevention 40, 1249-1252] have drawn attention to the discrepancy between self-reported and odometer-based driving distances and have argued against the credibility of the low-mileage bias. This paper has re-worked initial data from an early study which supported low-mileage bias, this time using odometer-based readings rather than self-reported mileage. Accepting the odometer readings at face value, the low-mileage bias remains evident, albeit at a reduced level.

Usefulness of off-road screening tests to licensing authorities when assessing older driver fitness to drive.

INTRODUCTION: There is a growing interest in quick and convenient, off-road tests of fitness to drive to assist licensing authorities in identifying the minority of older drivers at heightened crash risk. Two screening tests have been identified and assessed for their usefulness in a licensing context. METHOD: The research literature has been examined to identify available evaluation evidence relating to the two tests. In particular, studies that have quantified any association between test results and crash involvement in terms of relative risk have been analyzed for licensing implications. RESULTS: Performance on two tests--UFOV and MaryPODS--has been shown to have a consistent and statistically significant association with crash risk, including at-risk crashes. Overall, poor test performance has been associated with a two times or higher relative risk of crash involvement on both retrospective and prospective bases. This statistical association is seen as a necessary first step in further developing off-road screening tests. It is demonstrated, however, that the tests are presently too inaccurate to be used as a form of age-based assessment on a simple pass/fail basis and would result in large numbers of older drivers being needlessly taken from the road. It is also argued that these tests may hold promise when used for preselected groups of at-risk older drivers and when used to produce a threefold outcome ("pass," "'fail," and "uncertain, requiring further assessment"). CONCLUSIONS: At this time, no off-road screening test of fitness to drive currently can be justified if applied on a simple pass/fail basis to all drivers reaching a threshold age, as the sole determinant of licensing status.

An Australasian model license reassessment procedure for identifying potentially unsafe drivers.

Most licensing jurisdictions in Australia currently employ age-based assessment programs as a means to manage older driver safety, yet available evidence suggests that these programs have no safety benefits. This paper describes a community referral-based model license re assessment procedure for identifying and assessing potentially unsafe drivers. While the model was primarily developed for assessing older driver fitness to drive, it could be applicable to other forms of driver impairment associated with increased crash risk. It includes a three-tier process of assessment, involving the use of validated and relevant assessment instruments. A case is argued that this process is a more systematic, transparent and effective process for managing older driver safety and thus more likely to be widely acceptable to the target community and licensing authorities than age-based practices.

Do older drivers pose a risk to other road users?

OBJECTIVE: To investigate the extent to which older drivers pose a risk to other road users, relative to drivers of other ages, using Australian fatal crash data. METHOD: The principal data source was the Australian Transport Safety Bureau's National Fatalities Database, which has provided fatality numbers for the most recent available 10-year period (1988, 1990, 1992, 1994, and 1996-2001). For each driver age group ("target drivers"), fatality rates were calculated for the following categories of road users: target driver deaths, their passenger deaths, road users external to the target vehicle but killed in the crash involving the target driver, all road users killed other than target drivers, and all road users killed (including target drivers). Fatality rates were calculated on three bases: per population numbers in each age category, per licensed driver numbers in each age category, and per distance driven for each age category. The different road user fatality rates associated with drivers aged 80 years and older were compared to the rates associated with drivers from younger age categories. RESULTS: On a per population basis, older drivers had a significantly lower "all road users" fatality rate than all age groups bar one (RR for other age groups: 1.2-3.1) and these differences strengthened once target drivers were excluded (RR: 1.4-5.1), all differences significant. On a per licence basis, older drivers had significantly higher "all road users" fatality rate when compared to the rates for drivers aged 30-39 years through to 70-79 years (RR for these age groups: 0.5-0.7) but once the target drivers were excluded, older drivers' "all other road users & fatality rates for were significantly lower than for drivers aged 17-24 years to 30-39 (RR: 1.3-2.6) years. On a per-distance basis, older drivers had significantly higher all road users fatality rate when compared to the rates for all drivers aged 25-29 years through to 70-79 years (RR for these age groups: 0.1-0.4). Once the target drivers were excluded, older drivers' all other road users fatality rates remained significantly higher than for these other age groups (RR: 0.3-0.7) years. CONCLUSIONS: Based on two of the three bases (per population and per licence), it has been strongly asserted that overall, the older the driver, the less the threat to other road users--and particularly, the less the threat to road users external to the driver's vehicle. Drivers aged 80 years and older appeared to be the greatest threat to other road users only when per distance fatality rates were compared.

Determining older driver crash responsibility from police and insurance data.

This study aimed to determine the extent to which older drivers can be considered responsible for their crashes, to identify key factors in those crashes for which older drivers have been judged responsible, and to assess the extent to which older drivers' extra crash responsibility contributes to the road toll. Insurance claims from the State of Tasmania, Australia, for 1998-2002 were linked with police records for crashes involving drivers aged either 41-55 years or 65 years or older. Insurance and police data sets contained independent judgments of crash responsibility. There was a high level of agreement between the two sets of judgments, with older drivers judged around 1.5 times more likely to be responsible for their crashes than middle-aged drivers and, conversely, older drivers were around 0.6 as likely to be absolved from crash responsibility. It was concluded that older drivers' additional crash responsibility while valuable in explaining "what went wrong," currently makes only a small contribution to the overall road toll.

Older drivers do not have a high crash risk--a replication of low mileage bias.

The widespread claim that older drivers are overly involved in crashes has apparent support from crash data, especially when distance travelled is used as the exposure measure. However, independent of age, drivers travelling more kilometres will typically have lower crash rates per kilometre than those driving fewer kilometres. This paper uses Dutch travel survey data from a large sample of respondents to confirm previous research findings concerning the association between annual mileages driven and crash involvement. When the crash rates of drivers of different ages were compared after being matched for yearly driving distance, most drivers aged 75 years and above were indicatively safer than all other drivers. Only older drivers travelling less than 3000 km per year (just over 10% of all older drivers in the survey) gave any indication of elevated crash rates.

Effectiveness of mandatory license testing for older drivers in reducing crash risk among urban older Australian drivers.

Most licensing jurisdictions in Australia maintain mandatory assessment programs targeting older drivers, whereby a driver reaching a specified age is required to prove his or her fitness to drive through medical assessment and/or on-road testing. Previous studies both in Australia and elsewhere have consistently failed to demonstrate that age-based mandatory assessment results in reduced crash involvement for older drivers. However studies that have based their results upon either per-population or per-driver crash rates fail to take into account possible differences in driving activity. Because some older people maintain their driving licenses but rarely if ever drive, the proportion of inactive license-holders might be higher in jurisdictions without mandatory assessment relative to jurisdictions with periodic license assessment, where inactive drivers may more readily either surrender or lose their licenses. The failure to control for possible differences in driving activity across jurisdictions may be disguising possible safety benefits associated with mandatory assessment. The current study compared the crash rates of drivers in Melbourne, Australia, where there is no mandatory assessment and Sydney, Australia, where there is regular mandatory assessment from 80 years of age onward. The crash rate comparisons were based on four exposure measures: per population, per licensed driver, per distance driven, and per time spent driving. Poisson regression analysis incorporating an offset to control for inter-jurisdictional road safety differences indicated that there was no difference in crash risk for older drivers based on population. However drivers aged 80 years and older in the Sydney region had statistically higher rates of casualty crash involvement than their Melbourne counterparts on a per license issued basis (RR: 1.15, 1.02-1.29, p=0.02) and time spent driving basis (RR: 1.19, 1.06-1.34, p=0.03). A similar trend was apparent based on distance travelled but was of borderline statistical significance (RR: 1.11, 0.99-1.25, p=0.07). Collectively, it can be inferred from these findings that mandatory license re-testing schemes of the type evaluated have no demonstrable road safety benefits overall. Further research to resolve this on-going policy debate is discussed and recommended.