Some consequences of different older driver licensing procedures in Australia

Given both the expected growth in the number of older drivers and their over-involvement in fatal and serious injury crashes, there has been a world-wide call for improved licensing procedures to manage older driver safety. In particular, licensing authorities have been urged to move from mandatory assessment of all older drivers to assessment practices targeting only those at higher crash risk. The current study examined older driver fatal and serious injury crash involvement rates across all Australian States to determine a possible association with the different licensing procedures. In particular, older driver crash involvement rates in Victoria (where there is no age-based assessment program) have been compared with rates in other jurisdictions with assessment programs. Crash involvement rates have been calculated using two denominators: per population and per number of licensed drivers. Some data limitations notwithstanding, older drivers in jurisdictions with age-based mandatory assessment programs could not be shown to be safer than drivers in Victoria. Further, there is some indicative evidence that older drivers in Victoria may have a significantly safer record regarding overall involvement in serious casualty crashes.     

Error specific restrictions for older drivers: promoting continued independence and public safety

OBJECTIVES: To describe a population of older drivers with driving restrictions, their most common restrictions, and to compare restricted drivers to their safe and unsafe counterparts. Safe drivers are those who do not commit hazardous errors or traffic violations. Unsafe drivers are those who commit hazardous errors and/or traffic violations that place them in hazardous situations. Restricted drivers are those who have committed traffic or rule violations only under certain driving conditions. DESIGN: A retrospective, cross-sectional study with mixed methodology. SETTING: A clinical driving evaluation program within an academic geriatrics department. PARTICIPANTS: Drivers age 60+ (N=108) referred for clinical driving evaluation and who consented to allow their data to be used for research purposes. INTERVENTION: Drivers performing at an intermediate level driving fitness were issued error specific driving restrictions. MEASUREMENT: Driving evaluation included clock drawing test (CDT), mini-mental status exam (MMSE), Trailmaking, geriatric depression scale (GDS), and simulated driving. RESULTS: The three most common restrictions were limited driving distance (N=8), limited driving time (N=8), and daytime only driving (N=8). Safe, restricted, and unsafe drivers significantly differed on MMSE (F[2,104]=10.75, p<0.001), Trailmaking Part B (F[2,76]=9.96, p<0.001), CDT (F[2,98]=29.88, p<0.001), and total number of hazardous errors (F[2,97]=39.06, p<0.001). Tukey's test indicated safe and restricted drivers scored significantly better than unsafe drivers on MMSE (safe: p<0.001; restricted: p=0.008), CDT (p<0.001), and hazardous errors (p<0.001). Restricted and unsafe drivers required significantly more time to complete Trailmaking B than safe drivers (p=0.004). CONCLUSION: Preliminary data indicate restricted drivers perform more like safe than unsafe drivers. Driving simulation is instrumental in discerning error specific limitations and categorizing patients as conditionally safe. This clinical evaluation pilots an effective alternative to premature driving cessation.     

Trends in older driver crash involvement rates and survivability in the United States: An update

Objective

Previous research has shown that fatal crash involvement rates per licensed driver aged 70 and older declined significantly more per year in the United States than rates for middle-aged drivers aged 35–54 during 1997–2008, and per vehicle mile traveled from 1995–1996 to 2001–2002. Analyses of police-reported crash data during 1997–2005 indicated that the greater declines for older drivers were due to decreases in crash involvement and in the risk of dying in the crashes that occurred. The current study examined if trends in crash rates, crash involvements, and survivability persisted into more recent years.

Methods

Trends for drivers 70 and older were compared with trends for drivers aged 35–54 for U.S. national fatal passenger vehicle crash involvements per 100,000 licensed drivers during 1997–2012 and for U.S. national fatal passenger vehicle crash involvements per vehicle miles traveled in 1995–1996, 2001–2002, and 2008. Using police-reported crash data during 1997–2008 from 20 U.S. states, trends in involvement rates in non-fatal crashes of various severities per 100,000 licensed drivers and changes in the odds of death and the odds of death or serious injury in a crash were compared between older and middle-aged drivers.

Results

During 2007–2012, declines in national fatal crash involvement rates per licensed driver were similar for drivers 70 and older and middle-aged drivers (18 percent each). However, when considering the entire study period, fatal crash involvement rates continued to reflect a substantially larger decline for drivers 70 and older than for middle-aged drivers (42 vs. 30 percent per licensed driver during 1997–2012, 39 vs. 26 percent per vehicle mile traveled from 1995–2006 to 2008). When analyses of police-reported crash data were extended through 2008, non-fatal injury crash involvement rates per licensed driver declined more for older than for middle-aged drivers (39 vs. 30 percent), and unlike in prior research, average annual declines were significantly larger for drivers 80 and older. Property damage-only crash involvement rates similarly declined significantly more for older than for middle-aged drivers (15 vs. 3 percent). Drivers 70 and older in 1997 were 3.5 times more likely than middle-aged drivers to die in a crash, and this ratio declined to 3.2 by 2008.

Conclusions

Although declines in fatal crash involvement rates in recent years have not differed between older and middle-aged drivers, this did not undo earlier gains for older drivers. The recent slowing in the relative magnitude of the decline for older drivers may be related to the differential effect of the U.S. recession on fatal crash involvements of drivers in these age groups. The decreased likelihood of being involved in a crash of any severity and increased survivability when a crash occurred held when examining data through 2008, and for drivers 80 and older, significant declines in crash involvement relative to middle-aged drivers extended to non-fatal injury crashes.     

The potential effectiveness of young driver high-performance vehicle restrictions as used in Australia

Young drivers persistently have higher crash rates despite various countermeasures targeted at their risk factors and exposures. A potentially high risk situation for novice drivers may feasibly include the driving of high performance vehicles, which are subject to restrictions for probationary and restricted drivers in four Australian States. High performance vehicles are capable of high levels of acceleration and speed, which may encourage unsafe driving behaviours, particularly when driven by novice drivers, who may lack appropriate judgement and experience. This research sought to identify potential safety benefits of restrictions on certain vehicles for novice drivers using crash data from Australia and New Zealand, and vehicle licensing data from New Zealand.     

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.     

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.     

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.     

Effects of driver age and experience in abrupt-onset hazards

Novice drivers and older drivers are found to have the highest crash risk among all drivers and this has motivated many research studies into various aspects of novice and older drivers. Although age-related declines were expected, studies did not find older drivers to respond slower to hazards. This study examined the hazard detection and response latencies of 14 young novice drivers, 14 young experienced drivers, and 12 older experienced drivers, to abrupt-onset hazards. Older drivers were found to take longer times before fixating on an abrupt-onset road hazard but appeared to have insignificantly faster reaction times after the initial fixation. Hence, the overall response latency did not suggest any age effects. Older drivers also scanned the roadway less as compared to their younger counterparts. No effects of experience were found. The findings provided insight on age-related declines in hazard detection whose effects have been masked by other components of hazard response.     

Fragility versus excessive crash involvement as determinants of high death rates per vehicle-mile of travel among older drivers

Using multiple national data systems, the roles of fragility (susceptibility to injury) versus excessive crash involvement in the increased fatality risk of older drivers per vehicle-mile of travel (VMT) were estimated. For each age and gender group, deaths per driver involved in a crash (a marker of fragility) and drivers involved in crashes per VMT (a marker of excessive crash involvement) were computed. Compared with drivers ages 30-59, those younger than 20 and those 75 or older both had much higher driver death rates per VMT. The highest death rates per mile driven, 13-fold increases, were observed among drivers age 80 or older, who also had the highest death rates per crash. Fragility began to increase at ages 60-64 and increased steadily with advancing age, accounting for about 60-95% of the excess death rates per VMT in older drivers, depending on age group and gender. Among older drivers, marked excesses in crash involvement did not begin until age 75, but explained no more than about 30-45% of the elevated risk in this group of drivers; excessive crashes explained less of the risk among drivers ages 60-74. In contrast, crash over-involvement was the major factor contributing to the high risk of death among drivers younger than 20, accounting for more than 95% of their elevated death rates per VMT. Although both fragility and crash over-involvement contributed to the excess death rates among older drivers per VMT, fragility appeared to be of over-riding importance. These findings suggest that measures to improve the protection of older vehicle occupants in crashes should be vigorously pursued.     

Critical older driver errors in a national sample of serious U.S. crashes

Objective

Older drivers are at increased risk of crash involvement per mile traveled. The purpose of this study was to examine older driver errors in serious crashes to determine which errors are most prevalent.

Methods

The National Highway Traffic Safety Administration’s National Motor Vehicle Crash Causation Survey collected in-depth, on-scene data for a nationally representative sample of 5470 U.S. police-reported passenger vehicle crashes during 2005–2007 for which emergency medical services were dispatched. There were 620 crashes involving 647 drivers aged 70 and older, representing 250,504 crash-involved older drivers. The proportion of various critical errors made by drivers aged 70 and older were compared with those made by drivers aged 35–54.

Results

Driver error was the critical reason for 97% of crashes involving older drivers. Among older drivers who made critical errors, the most common were inadequate surveillance (33%) and misjudgment of the length of a gap between vehicles or of another vehicle’s speed, illegal maneuvers, medical events, and daydreaming (6% each). Inadequate surveillance (33% vs. 22%) and gap or speed misjudgment errors (6% vs. 3%) were more prevalent among older drivers than middle-aged drivers. Seventy-one percent of older drivers’ inadequate surveillance errors were due to looking and not seeing another vehicle or failing to see a traffic control rather than failing to look, compared with 40% of inadequate surveillance errors among middle-aged drivers. About two-thirds (66%) of older drivers’ inadequate surveillance errors and 77% of their gap or speed misjudgment errors were made when turning left at intersections. When older drivers traveled off the edge of the road or traveled over the lane line, this was most commonly due to non-performance errors such as medical events (51% and 44%, respectively), whereas middle-aged drivers were involved in these crash types for other reasons. Gap or speed misjudgment errors and inadequate surveillance errors were significantly more prevalent among female older drivers than among female middle-aged drivers, but the prevalence of these errors did not differ significantly between older and middle-aged male drivers. These errors comprised 51% of errors among older female drivers but only 31% among older male drivers.

Conclusions

Efforts to reduce older driver crash involvements should focus on diminishing the likelihood of the most common driver errors. Countermeasures that simplify or remove the need to make left turns across traffic such as roundabouts, protected left turn signals, and diverging diamond intersection designs could decrease the frequency of inadequate surveillance and gap or speed misjudgment errors. In the future, vehicle-to-vehicle and vehicle-to-infrastructure communications may also help protect older drivers from these errors.     

Driver licenses as a measure of older drivers' exposure: a methodological note

The limitations of the number of driver licenses as an estimate of driving exposure were demonstrated by comparing Finnish and Swedish driver licensing practices, licensing rates and accident rates of older drivers. In Sweden, there is no screening for older license holders, and most of them keep their licenses for life. In Finland, there is a heavy and costly medico-legal control system for older license holders, leading to both screening and self-screening. Consequently, in the two countries, the numbers of driver licenses do not reflect the numbers of active older drivers in the same manner. This difference affects the comparative accident statistics: with respect to population, Finland and Sweden have similar age trends in accidents risk, but with respect to the number of driver licenses, the Finnish older drivers seem to have a higher risk of accident than the Swedish ones. It is concluded that if group comparisons of accident risk are presented using the number of driver licenses as an estimate of exposure, the licensing legislation and practice should affect all the groups in an identical manner for the comparison to be valid.     

A strategy to reduce older driver injuries at intersections using more accommodating roundabout design practices

This paper briefly summarizes a laboratory study investigating strategies designed to improve the ability of our most vulnerable drivers, the elderly, to safely negotiate the most dangerous and demanding of all traffic situations--intersections--through increased use of modern roundabouts. Compared to conventional intersections, roundabouts have demonstrated the potential to significantly reduce the most injurious (angle) type of crashes and slow the operating speed of all vehicles, while maintaining a high capacity for moving traffic through an intersection. This research sought to develop and evaluate countermeasures with the potential to improve the perceived comfort, confidence, and/or safety of seniors in using roundabouts. Research methods included focus groups and structured interviews utilizing photographs, which had been edited to include novel traffic control devices. The results suggest that design elements that improve the path guidance for older drivers are necessary to encourage roundabout use by this group. Recommendations for improved practice related to advance warning signs, guide signs, yield treatments, directional signs, and exit treatments are presented.     

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.     

Stability of physical assessment of older drivers over 1 year

Older adults represent the fastest-growing population of drivers with a valid driver's licence. Also common in this age group are multiple chronic medical conditions that may have an effect on physical function and driving ability. Determining the reliability of physical measures used to assess older drivers’ functional ability is important to identifying those who are safe to continue driving. Most previous reliability studies of clinical physical measures of health used test–retest intervals shorter than those between patient visits with a clinician. In the present study we examined a more clinically representative interval of 1 year to determine the stability of commonly used physical measures collected during the Candrive II prospective cohort study of older drivers. Reliability statistics indicate that the sequential finger–thumb opposition, rapid pace walk and the Pelli–Robson contrast sensitivity tests have adequate stability over 1 year. Poor stability was observed for the one-legged stance and Snellen visual acuity test. Several assessments with nominal data (Marottoli method [functional neck range of motion], whispered voice test, range of motion and strength testing) lacked sufficient variability to conduct reliability analyses; however, a lack of variability between test days suggests consistency over a 1-year time frame. Our results provide evidence that specific physical measures are stable in monitoring functional ability over the course of a year.     

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.     

An examination of the environmental,driver and vehicle factors associated with the serious and fatal crashes of older rural drivers

Motor vehicle crashes involving rural drivers aged 75 years and over are more than twice as likely to result in a serious or fatal injury as those involving their urban counterparts. The current study examined some of the reasons for this using a database of police-reported crashes (2004–2008) to identify the environmental (lighting, road and weather conditions, road layout, road surface, speed limit), driver (driver error, crash type), and vehicle (vehicle age) factors that are associated with the crashes of older rural drivers. It also determined whether these same factors are associated with an increased likelihood of serious or fatal injury in younger drivers for whom frailty does not contribute to the resulting injury severity. A number of environmental (i.e., undivided, unsealed, curved and inclined roads, and areas with a speed limit of 100 km/h or greater) and driver (i.e., collision with a fixed object and rolling over) factors were more frequent in the crashes of older rural drivers and additionally associated with increased injury severity in younger drivers. Moreover, when these environmental factors were entered into a logistic regression model to predict whether older drivers who were involved in crashes did or did not sustain a serious or fatal injury, it was found that each factor independently increased the likelihood of a serious or fatal injury. Changes, such as the provision of divided and sealed roads, greater protection from fixed roadside objects, and reduced speed limits, appear to be indicated in order to improve the safety of the rural driving environment for drivers of all ages. Additionally, older rural drivers should be encouraged to reduce their exposure to these risky circumstances.     

Factors influential in making an injury severity difference to older drivers involved in fixed object-passenger car crashes

To identify factors influencing severity of injury to older drivers in fixed object-passenger car crashes, two sets of sequential binary logistic regression models were developed. The dependent variable in one set of models was driver injury severity, whereas for the other it was the crash severity (most severe injury in the crash). For each set of models, crash or injury severity was varied from the least severity level (no injury) to the highest severity level (fatality) and vice versa. The source of data was police crash reports from the state of Florida. The model with the best fitting and highest predictive capability was used to identify the influence of roadway, environmental, vehicle, and driver related factors on severity. Travel speed, restraint device usage, point of impact, use of alcohol and drugs, personal condition, gender, whether the driver is at fault, urban/rural nature and grade/curve existence at the crash location were identified as the important factors for making an injury severity difference to older drivers involved in single vehicle crashes.     

Older driver distraction: A naturalistic study of behaviour at intersections

This study examined older driver engagement in distracting behaviours (secondary activities) at intersections using naturalistic driving data from a larger study based in Melbourne, Australia. Of interest was whether engagement in secondary activities at intersections was influenced by factors such as driver gender and situational variables, in particular, those relating to the complexity of the driving environment. Specifically we expected that when making left/right turns, older drivers would reduce the proportion of time engaged in secondary behaviours at intersections which required gap judgements (partly controlled or uncontrolled) compared with intersections that were fully controlled by traffic signals. Consideration was given to engagement in secondary activity with hands off the wheel and when the vehicle was moving versus stationary. Older drivers aged between 65 and 83 years drove an instrumented vehicle (IV) on their regular trips for approximately two weeks. The IV was equipped with a video camera system, enabling recording of the road environment and driver and a data acquisition unit, enabling recording of trip distance, vehicle speed, braking, accelerating, steering and indicator use. Driving experience and demographics were collected and functional abilities were assessed using the Useful Field of View (UFOV), Trail Making Test B, Mini Mental Status Examination (MMSE), visual acuity and contrast sensitivity. The study yielded a total of 371 trips with 4493 km (99.8 h) of naturalistic driving data including 1396 left and right turns. Trips were randomly selected from the dataset and in-depth analysis was conducted on 200 intersection manoeuvres (approximately 50% left turns, 50% right turns). The most frequently observed secondary activities were scratching/grooming (42.5%), talking/singing (30.2%) and manipulating the vehicle control panel (12.2%). Glances “off road” 2 s or longer were associated with reading, reaching and manipulation of the vehicle control panel. Hands off the wheel was associated with reading. Key parameters associated with the percent of intersection time that drivers engaged in secondary activities were intersection complexity, vehicle status (moving vs. stationary) and traffic density. In conclusion, older drivers appeared to engage selectively in secondary activities according to roadway/driving situations, supporting the notion that drivers self-regulate by engaging in secondary tasks less frequently when the driving task is more challenging compared with less challenging manoeuvres.     

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.     

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.