Development and evaluation of a Driving Observation Schedule (DOS) to study everyday driving performance of older drivers

This paper describes the development and evaluation of an on-road procedure, the Driving Observation Schedule (DOS), for monitoring individual driving behavior. DOS was developed for use in the Candrive/Ozcandrive five-year prospective study of older drivers. Key features included observations in drivers’ own vehicles, in familiar environments chosen by the driver, with start/end points at their own homes. Participants were 33 drivers aged 75+ years, who drove their selected route with observations recorded during intersection negotiation, lane-changing, merging, low speed maneuvers and maneuver-free driving. Driving behaviors were scored by a specialist occupational therapy driving assessor and another trained observer. Drivers also completed a post-drive survey about the acceptability of DOS. Vehicle position, speed, distance and specific roadways traveled were recorded by an in-vehicle device installed in the participant's vehicle; this device was also used to monitor participants’ driving over several months, allowing comparison of DOS trips with their everyday driving. Inter-rater reliability and DOS feasibility, acceptability and ecological validity are reported here. On average, drivers completed the DOS trip in 30.48 min (SD = 7.99). Inter-rater reliability measures indicated strong agreement between the trained and the expert observers: intra-class correlations (ICC) = 0.905, CI 95% 0.747–0.965, p < 0.0001; Pearson product correlation, r (18) = .83, p < 0.05. Standard error of the measurement (SEM), method error (ME) and coefficient of variation (CV) measures were consistently small (3.0, 2.9 & 3.3%, respectively). Most participants reported being ‘completely at ease’ (82%) with the driving task and ‘highly familiar with the route’ (97%). Vehicle data showed that DOS trips were similar to participants’ everyday driving trips in roads used, roadway speed limits, drivers’ average speed and speed limit compliance. In summary, preliminary findings suggest that DOS can be scored reliably, is of feasible duration, is acceptable to drivers and representative of everyday driving. Pending further research with a larger sample and other observers, DOS holds promise as a means of quantifying and monitoring changes in older drivers’ performance in environments typical of their everyday driving.     

Gender differences among older drivers in a comprehensive driving evaluation

Research studies typically consider older drivers as a homogenous group and do not report on the influence of gender on driving performance. Prior studies report that females are over-represented in crashes compared to males, caused by errors of yielding, gap acceptance, and speed regulation, all of which are assessed in a comprehensive driving evaluation (CDE). In a sample of 294 community dwelling older drivers, we examined and compared specific and total driving errors of both genders, and determined predictors of gender-specific driving errors and pass/fail outcomes who completed a CDE assessed by a certified driving rehabilitation specialist. No differences in specific or total number of driving errors on the CDE were found between older males (Mean age 73.4 ± 6.0) and older females (Mean age 73.8 ± 5.7). Education, days of driving, Useful Field of View™ (UFOV), Rapid Paced Walk Test (RPW) and the Mini-Mental State Exam (MMSE) were all independent predictors of failing a road test for both genders (p < 0.05). However, older females were 22% less likely than older males to fail an on-road test. Within group comparisons showed that older males and females >75 years were 3.2 and 3.5 times more likely to fail the on-road test compared to younger males and females (aged between 63 and 75), respectively. Our findings suggest that focusing on older old (75+) and old–old (85+) age groups may be more efficient for future investigations of driving performance.     

Self-rated driving and driving safety in older adults

Many U.S. states rely on older adults to self-regulate their driving and determine when driving is no longer a safe option. However, the relationship of older adults’ self-rated driving in terms of actual driving competency outcomes is unclear. The current study investigates self-rated driving in terms of (1) systematic differences between older adults with high (good/excellent) versus low (poor/fair/average) self-ratings, and (2) the predictive nature of self-rated driving to adverse driving outcomes in older adults (n = 350; mean age 73.9, SD = 5.25, range 65–91). Adverse driving outcomes included self-reported incidences of (1) being pulled over by the police, (2) receiving a citation, (3) receiving a recommendation to cease or limit driving, (4) crashes, and (5) state-reported crashes. Results found that older drivers with low self-ratings reported more medical conditions, less driving frequency, and had been given more suggestions to stop/limit their driving; there were no other significant differences between low and high self-raters. Logistic regression revealed older drivers were more likely to have a state-reported crash and receive a suggestion to stop or limit driving. Men were more likely to report all adverse driving outcomes except for receiving a suggestion to stop or limit driving. Regarding self-rated driving, older adults with high ratings were 66% less likely (OR = 0.34, 95% CI = 0.14–0.85) to have received suggestions to limit or stop driving after accounting for demographics, health and driving frequency. Self-ratings were not predictive of other driving outcomes (being pulled over by the police, receiving a citation, self-reported crashes, or state-reported crashes, ps > 0.05). Most older drivers (85.14%) rated themselves as either good or excellent drivers regardless of their actual previous citation or crash rates. Self-rated driving is likely not related to actual driving proficiency as indicated by previous crash involvement in older adults. Suggestions from other individuals to limit or cease driving may be more influential on self-ratings.     

Measuring situational avoidance in older drivers: An application of Rasch analysis

Situational avoidance is a form of driving self-regulation at the strategic level of driving behaviour. It has typically been defined as the purposeful avoidance of driving situations perceived as challenging or potentially hazardous. To date, assessment of the psychometric properties of existing scales that measure situational avoidance has been sparse. This study examined the contribution of Rasch analysis to the situational avoidance construct. Three hundred and ninety-nine Australian drivers (M = 66.75, SD = 10.14, range: 48–91 years) completed the Situational Avoidance Questionnaire (SAQ). Following removal of the item Parallel Parking, the scale conformed to a Rasch model, showing good person separation, sufficient reliability, little disordering of thresholds, and no evidence of differential item functioning by age or gender. The residuals were independent supporting the assumption of unidimensionality and in conforming to a Rasch model, SAQ items were found to be hierarchical or cumulative. Increased avoidance was associated with factors known to be related to driving self-regulation more broadly, including older age, female gender, reduced driving space and frequency, reporting a change in driving in the past five years and poorer indices of health (i.e., self-rated mood, vision and cognitive function). Overall, these results support the use of the SAQ as a psychometrically sound measure of situational avoidance. Application of Rasch analysis to this area of research advances understanding of the driving self-regulation construct and its practice by drivers in baby boomer and older adult generations.     

Health literacy of older drivers and the importance of health experience for self-regulation of driving behaviour

This study provides much needed information on the education level of older drivers regarding the impact of health conditions and medications on personal driving safety, where they source this information, and how this knowledge influences self-regulation of driving. Random and convenience sampling secured 322 Australian drivers (63.9% males) aged 65 years and over (M = 77.35 years, SD = 7.35) who completed a telephone interview. The majority of respondents (86%) had good knowledge about health conditions (health knowledge) and driving safety, however more than 50% was classified as having poor knowledge on the effects of certain medications (medication knowledge) and driving safety. Poorer health knowledge was associated with a reduced likelihood of driving over 100 km in adjusted models. Being older and having more than one medical condition was found to increase the likelihood of self-regulation of driving. Results indicate that health knowledge was less important for predicting driving behaviour than health experience. Of great interest was that up to 85.7% of respondents reported not receiving advice about the potential impact of their medical condition and driving from their doctor. The findings indicate a need for improved dissemination of evidence-based health information and education for older drivers and their doctors.     

Impact of mandating a driving lesson for older drivers at license renewal in Japan

In Japan, a driving lesson consisting of a lecture, a driver aptitude test, on-road driving assessment and a discussion session was added to the driving license renewal procedure for drivers aged 75 years or older in 1998 and for drivers aged 70 years or older in 2002. We investigated whether these additions contributed to a reduction in at-fault motor vehicle collisions (MVCs) by examining the trend of the at-fault MVC rates per licensed driver and the rate ratios of the older drivers relative to those aged 65–69 years for the years 1986–2011. All data were derived from nationwide traffic statistics. If the introduction of the lesson was effective in reducing at-fault MVCs of older drivers, the rate ratio should have declined, given that the lesson targeted only the older drivers. We found this was not the case, i.e., there was no declining trend in the at-fault MVC rate ratios of both drivers aged 75 years or older and drivers aged 70 years or older, relative to drivers aged 65–69 years, after the driving lesson at license renewal became mandatory for these older drivers. Therefore, the mandatory lesson for the older drivers at license renewal needs to be reconsidered.     

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.     

Self-rated driving performance among elderly drivers referred for driving evaluation

PURPOSE: To explore whether elderly drivers of varying driving skill levels (1) differ in their perception of their driving evaluation performance and (2) determine if self-rated driving evaluation performance is related to cognitive ability. METHODS: One hundred and fifty-two drivers aged 65 years or older and referred for a driving evaluation were enrolled into the study. Subjects were asked the question, "how well do you think you will perform today on your driving evaluation compared to others your own age?" Subjects also completed the Mini-Mental State Exam and a 30-min drive on a STISIM Drivetrade mark simulation (Systems Technology, Inc., Hawthorne, CA). Only 47 subjects completed both the simulated drive and self-rated item. RESULTS: Sixty-five percent of drivers rated themselves as performing better on a driving test than others of their age. Another 31.9% felt they would perform the same as others of their age on a driving test. A 50.0% of those considering themselves "a little better" and 52.9% of those considering themselves "a lot better" had an unsafe driving performance. As self-rated driving evaluation performance increased, there was a significantly increased risk of unsafe driving (p=0.02) in the study population. Drivers who considered themselves at least a little better than others of their age were over four times more likely to be unsafe drivers compared to others who believed they were comparable to or worse than other drivers of their age (RR=4.13, 95% CI=1.08-15.78). There was no significant difference in MMSE between self-rating groups (p=0.76). CONCLUSION: Older drivers assign high ratings to their driving performance, even in the presence of suspected skill decline. Cognitive ability was not related to self-rated driving evaluation performance.     

Self-regulatory driving practices among older adults: health, age and sex effects

The purpose of this study was to better understand how older adults self-regulate driving, and to identify differences by age, sex, and health-related functioning. Michigan drivers over age 64 were surveyed by telephone (n=961, age [mu=74.2, sigma=5.8], 56% female) about their driving-related behaviors, physical functioning, and health. Respondents were presented with scenarios involving driving to an important appointment under adverse conditions (rainy stormy weather, on alternate route in heavy freeway traffic, 200-mile trip on unfamiliar roads). Generalized logit models examined outcomes for each scenario: driving as usual, driving with modifications, and not driving. Results indicate that the effect of sex on self-regulation was significant and greater than that of age and physical functioning. Women were more likely to self-regulate by not driving. Odds ratios and 95% confidence limits for each scenario for women vs. men are 6.8 (3.8-2.0), 6.5 (3.6-12.0), and 17.7 (11.0-28.6). The effect of sex on self-regulation by modifying driving was smaller and significant only in scenarios 2 and 3. Women were more likely then men to modify driving for scenario 2 (odds ratio, 3.0 (2.0-4.5)) and scenario 3 (odds ratio 4.4 (3.1-0.1)). Overall, the study finds the relative effect of sex on self-regulation greater than that of age and physical functioning for conditions examined.     

Personality traits and executive functions related to on-road driving performance among older drivers

The present study investigated how executive functions and personality traits are related with driving performance among older drivers. Forty-two participants aged 60 and over were recruited to complete a battery of cognitive tests, measures of personality traits and an on-road driving test. Significant correlations were found between poor driving performances and low scores on tests assessing shifting and updating functions. In addition, extraversion had a negative relation with driving performance and made the only contribution, among the psychological factors, to the prediction of driving performance. Finally, gender and age emerged as the best predictors of on-road driving performance. Gender, personality traits and executive functions should be taken into account when studying safety among older drivers.     

Cognitive screening of older drivers does not produce safety benefits

Although screening policies for older drivers based on chronological age are widely used in many countries, previous research has shown that increasing age does not cause higher crash rates and that consequently, chronological age per se is at best only a weak predictor of safe driving performance. Previous research on age-based mandatory screening of older drivers has not been able to demonstrate any safety benefits from screening measures.     

The acceptability to older drivers of different types of licensing restriction

The primary objective of this study was to determine the acceptability of various driving restrictions to older drivers. Licensed drivers aged 65 years or more living in the community in the Ottawa, Ontario area were recruited by means of posters and advertisements in regional and local newspapers. We recruited 86 subjects, 56 men and 30 women with a mean age of 75 years (50 urban and 36 rural residents). The subjects completed a one-hour interview with one of two trained study nurses during which their driving restriction preferences (utilities) were determined using a modified standard gamble technique. Highly endorsed restrictions included regular assessment by the Ministry of Transportation (mean utility 0.94), driving with vehicle adaptations (0.94) and daytime driving only (0.93). Less acceptable restrictions included avoidance of roads with a speed limit greater than 60 km/h (0.50), limitation of destinations (0.45), driving only within a 10-km radius of home (0.45) and requirement of another licensed driver in the vehicle (0.42). Our subjects' preferences appeared to be inversely related to the impact on autonomy and the ability to access the community. These findings may be useful to motor transport administrators in designing effective restricted licensing programs that are acceptable to older drivers.     

Personality and attitudes as predictors of risky driving among older drivers

Although there are several studies on the effects of personality and attitudes on risky driving among young drivers, related research in older drivers is scarce. The present study assessed a model of personality-attitudes-risky driving in a large sample of active older drivers. A cross-sectional design was used, and structured and anonymous questionnaires were completed by 485 older Italian drivers (Mean age = 68.1, SD = 6.2, 61.2% males). The measures included personality traits, attitudes toward traffic safety, risky driving (errors, lapses, and traffic violations), and self-reported crash involvement and number of issued traffic tickets in the last 12 months. Structural equation modeling showed that personality traits predicted both directly and indirectly traffic violations, errors, and lapses. More positive attitudes toward traffic safety negatively predicted risky driving. In turn, risky driving was positively related to self-reported crash involvement and higher number of issued traffic tickets. Our findings suggest that theoretical models developed to account for risky driving of younger drivers may also apply in the older drivers, and accordingly be used to inform safe driving interventions for this age group.     

Declines in fatal crashes of older drivers: changes in crash risk and survivability

Objectives

Previous research has found that older driver fatal crash involvement rates per licensed driver declined substantially in the United States during 1997–2006 and declined much faster than the rate for middle-age drivers. The current study examined whether the larger-than-expected decline for older drivers extended to nonfatal crashes and whether the decline in fatal crash risk reflects lower likelihood of crashing or an improvement in survivability of the crashes that occur.

Methods

Trends in the rates of passenger vehicle crash involvements per 100,000 licensed drivers for drivers 70 and older (older drivers) were compared with trends for drivers ages 35–54 (middle-age drivers). Fatal crash information was obtained from the Fatality Analysis Reporting System for years 1997–2008, and nonfatal crash information was obtained from 13 states with good reporting information for years 1997–2005. Analysis of covariance models compared trends in annual crash rates for older drivers relative to rates for middle-age drivers. Differences in crash survivability were measured in terms of the odds of fatality given a crash each year, and the historical trends for older versus middle-age drivers were compared.

Results

Fatal crash involvement rates declined for older and middle-age drivers during 1997–2008 (1997–2005 for the 13 state subsample), but the decline for drivers 70 and older far exceeded the decline for drivers ages 35–54 (37 versus 23 percent, nationally; 22 versus 1 percent, 13 states). Nonfatal injury crash involvement rates showed similarly larger-than-expected declines for older drivers in the 13 state subsample, but the differences were smaller and not statistically significant (27 percent reduction for older drivers versus 16 percent for middle-age drivers). Property-damage-only crash involvement rates declined for older drivers (10 percent) but increased for middle-age drivers (1 percent). In 1997, older drivers were 3.5 times more likely than middle-age drivers to die in police-reported crashes (6.2 versus 1.8 deaths per 1000 crashes), but this difference was reduced during the 9-year study period to 2.9 times, as the rate of older drivers dying in a crash declined (5.5 deaths per 1000 crashes in 2005) and the death risk remained relatively stable for middle-age drivers.

Conclusions

Contrary to expectations based on increased licensure and travel by older drivers, their fatal crash risk has declined during the past decade and has declined at a faster rate than for middle-age drivers. The decreased risk for older drivers appears to extend not only to nonfatal injury crashes but also to property-damage-only crashes, at least as reported to police in the 13 states included in the nonfatal injury analysis. Although insurance collision data suggest that overall crash risk of older drivers may not be changing relative to middle-age drivers, the current analysis indicates that the reduced fatality risk of older drivers reflects both less likelihood of being involved in a police-reported crash and greater likelihood that they will survive when they do crash.     

The efficacy of an educational intervention in promoting self-regulation among high-risk older drivers

Visual processing impairment increases crash risk among older drivers. Many older drivers meet the legal requirements for licensing despite having vision impairments that elevate crash risk. In this study, 365 older drivers who were licensed, visually-impaired, and crash-involved in the prior year were randomly assigned to an intervention group or usual-eye-care control group to evaluate the efficacy of an educational intervention that promoted the performance of self-regulatory practices. The educational curriculum was designed to change self-perceptions about vision impairment and how it can impact driver safety and to promote the avoidance of challenging driving situations through self-regulation, leading to reductions in driving exposure. Analyses compared the intervention and control groups at pre-test and 6 months post-test with respect to self-reported perceptions about vision and driving practices. At post-test, drivers who had received the educational intervention were more likely to acknowledge that the quality of their eyesight was less than excellent, report a higher frequency of avoiding challenging driving situations (e.g. left-turns) and report performing more self-regulatory practices (e.g. three right-turns) as compared to controls. Additionally, drivers in the educational intervention group reported significantly fewer days, fewer places and fewer trips made per week as compared to those not receiving the educational intervention. These findings imply that visually-impaired older drivers at higher risk for crash involvement may benefit from educational interventions by reducing their driving exposure and increasing their avoidance of visually challenging driving situations. A critical future step in this research program will be to examine whether this educational intervention has an impact on the safety of these high-risk older drivers by reducing their crash involvement in the years following the educational intervention.     

Differential impact of personality traits on distracted driving behaviors in teens and older adults

ObjectiveTo determine the impact of personality on distracted driving behaviors.MethodParticipants included 120 drivers (48 teens, 72 older adults) who completed the 45-item Big Five Personality questionnaire assessing self-reported personality factors and the Questionnaire Assessing Distracted Driving (QUADD) assessing the frequency of distracted driving behaviors. Associations for all five personality traits with each outcome (e.g., number of times texting on the phone, talking on the phone, and interacting with the phone while driving) were analyzed separately for teens and older adults using negative binomial or Poisson regressions that controlled for age, gender and education.ResultsIn teens, higher levels of openness and conscientiousness were predictive of greater reported texting frequency and interacting with a phone while driving, while lower levels of agreeableness was predictive of fewer reported instances of texting and interacting with a phone while driving. In older adults, greater extraversion was predictive of greater reported talking on and interacting with a phone while driving. Other personality factors were not significantly associated with distracted driving behaviors.ConclusionsPersonality traits may be important predictors of distracted driving behaviors, though specific traits associated with distracted driving may vary across age groups. The relationship between personality and distracted driving behaviors provides a unique opportunity to target drivers who are more likely to engage in distracted driving behavior, thereby increasing the effectiveness of educational campaigns and improving driving safety.     

Development of a valid measurement instrument to understand self-regulatory driving practices among older drivers in Malaysia

Self-regulatory driving is a term used to describe a strategy used by older drivers to preserve mobility and safety, through the adjustment of driving behaviors to match declining physical functions. It can be regarded as a way to prolong driving, or as a process leading to the cessation of driving. Previous studies have striven to explore and understand how older drivers self-regulate their driving. This paper aims to provide an overview of the relevant theories, to explicate the factors that contribute to the adoption of self-regulated driving and the scales used to measure self-regulatory behaviors. This paper also reports on the development and psychometric testing of a Self-Regulatory Driving Practices (SRDP) scale in the Malaysian context. Based on the reviewed theories, adoption of self-regulatory driving practices is a process and involves cognitive thinking that reflects a set of actions. Existing instruments to measure self-regulatory driving practices have been developed and used to identify the behavioral components of self-regulation. Based on literature reviews and a thematic analysis from focus group discussions, a SRDP scale was developed, accommodating the Malaysian context. There were 498 surveys completed by older drivers for further psychometric testing purposes. Results revealed that the final 12-item SRDP scale (α = 0.81) consists of four subscales that are planning, avoidance, reduction and alternatives. Suggestions for future research are also recommended.     

Older drivers and road safety: the acceptability of a range of intervention measures

A survey questionnaire was used to ascertain the views of 1932 UK drivers aged between 50 and 90 on a range of measures designed to promote safer driving among the elderly. Factor analysis of the items produced six factors, relating to statistically distinct types of measure. Differences in acceptability on the basis of age and sex were explored. Ratings of the effectiveness of each measure revealed little consensus about which measures would be most effective. Compulsory re-testing after a driving ban, a police power to require an assessment of the driving of anyone observed driving in a risky manner, and a requirement for opticians to report to the licensing authority any driver with sight problems likely to affect driving emerged as the individual measures offering the best combination of acceptability and perceived effectiveness.     

Examination of driving comfort and self-regulatory practices in older adults using in-vehicle devices to assess natural driving patterns

Several studies have shown that age, gender, visual problems and confidence are associated with self-regulatory practices such as reduced exposure and avoidance of night and highway driving. To date, however, self-regulation has only been examined through self-report. The purpose of this study was to further our understanding of the association between driver characteristics, perceptions and self-regulation by monitoring the patterns of 61 drivers (mean age 80.4 ± 5.5; 59% women) for one week using in-vehicle devices. Usual self-regulatory practices were assessed using the Situational Driving Frequency (SDF) and Avoidance (SDA) Scales, while perceptions were measured using the Driving Comfort and Perceived Driving Abilities Scales. Additional evidence for test-retest reliability was obtained with a separate sample of 39 older drivers. Lower comfort and poorer perceived abilities were significantly related to actual behavior: reduced exposure (km, duration) in general and at night, average and maximum radii from home and driving in challenging situations (such as on highways). Neither sex nor age was associated with any of the driving indicators. While longitudinal studies are required to determine temporality (when drivers change their behavior) and directionality (does lower comfort lead to driving restrictions or vice versa), this is the first study to demonstrate that driver perceptions are associated with actual self-regulatory practices.     

Predictors of driving exposure and avoidance in a field study of older drivers from the state of Maryland

Using structural equation modeling techniques, this study examines causal models of driving avoidance and exposure among older adults. Prior studies have revealed that past incidence of falls, Useful Field of View (UFOV) test performance, and Trails Making test performance are predictive of subsequent motor vehicle crash involvement [Owsley, C., Ball, K., McGwin Jr., G., Sloane, M.E., Roenker, D.L., White, M.F., Overley, E.T., 1998. Visual processing impairment and risk of motor vehicle crash among older adults. J. Am. Med. Assoc. 279 (14), 1083-1088; Sims, R.V., McGwin, G., Pulley, L., Roseman, J.M., 2001. Mobility impairments in crash-involved older drivers. J. Aging Health 13 (3), 430-438; Stutts, J.C., 1998. Do older drivers with visual nd cognitive impairments drive less? J. Am. Geriatr. Soc. 46, 854-861]. Data analyses used these indices, along with age, health, measures of physical functioning, and additional measures of cognitive functioning, to examine driving exposure and avoidance behaviors. A field sample of 4,234 drivers, 55 years of age and older, were recruited from the Maryland Motor Vehicles Administration after renewing their driver's licenses. A performance-based assessment, which included the Gross Impairment Screening battery and task 2 of the UFOV test, was completed by participants. A sub-sample of participants (n=815) were interviewed by telephone about their health and mobility 3-6 months following the initial assessment at a renewal center. In addition to age and gender, latent variables for health status, physical functioning, cognitive functioning, driving exposure, and driving avoidance were created. Direct and indirect causal paths were specified. Age, gender, health status, and cognitive functioning had direct effects on both driving exposure and driving avoidance; physical functioning did not have a direct effect on driving exposure or avoidance. The implications of these findings are discussed as they relate to designing interventions to promote mobility.