Dennis P. McCarthy

Predictability of clinical assessments for driving performance

PROBLEM As the number of older drivers grows, it is increasingly important to accurately identify at-risk drivers. This study tested clinical assessments predictive of real-time driving performance. METHOD Selected assessment tools considered important in the identification of at-risk older drivers represented the domains of vision, cognition, motor performance, and driving knowledge. Participants were administered the battery of assessments followed by an on-road test. A univariate analysis was conducted to identify significant factors (<.05) to be included in a multivariate regression model. RESULTS Assessments identified as independently associated with driving performance in the regression model included: FACTTM Contrast sensitivity slide-B, Rapid Pace Walk, UFOV rating, and MMSE total score. DISCUSSION The domains of vision, cognitive, and motor performance were represented in the predictive model. SUMMARY Due to the dynamic nature of the driving task, it is not likely that a single assessment tool will identify at risk drivers. IMPACT ON INDUSTRY By standardizing the selection of clinical assessments used in driving evaluations, practitioners should be able to provide services more efficiently, more objectively, and more accurately to identify at-risk drivers.

Useful Field of View as a Reliable Screening Measure of Driving Performance in People With Parkinson's Disease: Results of a Pilot Study

Purpose: To determine the correlations of the Useful Field of View (UFOV), compared to other clinical tests of Parkinsons disease (PD); vision; and cognition with measures of on-road driving assessments and to quantify the UFOVs ability to indicate passing/failing an on-road test in people with PD. Methods: Nineteen randomly selected people with idiopathic PD, mean age = 74.8 (6.1), 14 (73.7%) men, 18 (94.7%) Caucasians, were age-matched to 104 controls without PD. The controls had a mean age of 75.4 (6.4), 59 (56.7%) men, 96 (92.3%) Caucasians. Both groups were referred for a driving evaluation after institutional review board approval. Results: Compared to neuropsychological and clinical tests of vision and cognition, the UFOV showed the strongest correlations (r > .75, p < 0.05) with measures of failing a standardized road test and number of driving errors. Among PD patients, the UFOV Risk Index score of 3 (range 1–5) was established as the optimal cutoff value for passing the on-road test, with sensitivity 87 percent and specificity 82 percent, AUC = 92 percent (SE 0.61, p = .002). Similarly, the UFOV 2 (divided attention) optimum cutoff value is 223 ms (range 16–500 ms), sensitivity 87.5 percent, specificity 81.8 percent, AUC = 91 percent (SE 0.73, p = .003). The UFOV 3 (selected attention) optimal cutoff value is 273 ms (range 16–500 ms), sensitivity 75 percent, specificity 72.7 percent, AUC = 87 percent (SE 0.81, p = .007). Conclusion: In this pilot study among PD patients, the UFOV may be a superior screening measure (compared to other measures of disease, cognition, and vision) for predicting on-road driving performance but its rigor must be verified in a larger sample of people with PD.

The Impact of Roadway Intersection Design on Driving Performance of Young and Senior Adults

Objective. To test the effectiveness of the FHWA guidelines for intersection design. Methods. In an experimental design we used kinematics measures from an instrumented vehicle and behavioral (error) data collected during on-road evaluations to quantify the effects of improved versus unimproved intersections (turn phase) and to determine if these intersections were safer (vehicular stability and driver confidence) for both older (65–85 years) and younger (25 –45) drivers. We analyzed kinematics data with a 2 × 2 repeated measures ANOVA and behavioral data (driving errors yes, no) with Wilcoxon sign rank test (within subject variable: intersection improved vs. unimproved) and Wilcoxon rank sum test (between subject variable: age, younger vs. older driver). Results. Kinematics measures (turn phase), showed three maneuvers had statistically significantly lesser side forces (measured by lateral acceleration and combined acceleration) for the improved conditions, and four maneuvers had statistically significantly greater, yet appropriate, speeds for the improved conditions. Lesser side forces indicated improved lateral stability and increased speed indicated greater confidence. Drivers made fewer errors on two of the improved intersections; but across all maneuvers, older drivers appeared to make fewer errors on the improved intersections. Conclusions. This study brings empirical intersection design and safety information for engineers and city planners to consider as they plan and develop intersections. Future researchers may want to use the conceptual and analytical framework of this study to determine the effectiveness of other FHWA guidelines. Given that these intersection design guidelines benefit younger and older drivers alike, plausible policy-making opportunities are opened in the design of safe roadway systems, to benefit the broad spectrum of adult drivers.

The Impact of Intersection Design on Simulated Driving Performance of Young and Senior Adults

Purpose. The Federal Highway Administration (FHWA) proposed guidelines for highway design to increase the safe driving ability of older drivers; however, little empirical evidence exists to support the effectiveness of these guidelines. The purpose of this study was to investigate the effects of implementing these guidelines (in 4 pairs of intersections) on safe driving performance of older and younger drivers using a high-fidelity driving simulator. Design and Methods. We replicated four intersection pairs (improved versus unimproved) in a high-fidelity, virtual reality driving simulator. Simulator scenarios were created from actual road locations, replicating road geometrics and traffic control devices. The simulators controls were integrated with an actual vehicle to make the driving experience as realistic as possible. Kinematic measures were obtained from the simulator in conjunction with driving errors recorded by trained driving evaluators sitting in the cab of the car. Thirty-nine subjects, 19 younger and 20 older adults, participated in the study. Results. For the kinematic data we found greater lateral control, as indicated by significantly smaller maximum yaw during the turn phase, at all of the improved intersections when compared to the unimproved intersections. We found some significant age differences, but mostly in only one of the intersection-pairs. For the behavioral data, there were significant differences in driving errors between improved and unimproved intersections in two intersection-pairs; however, there were no significant differences in driving errors between the older and younger drivers. Implications. The findings suggest that both young and older drivers may benefit from roadways with safety features recommended by the FHWA guidelines as indicated by the increased lateral control of the vehicle when negotiating these intersections. These findings generate critical information for those involved in the design of roadway systems.

Relationship of Health Status, Functional Status, and Psychosocial Status to Driving Among Elderly with Disabilities

SUMMARY Objective. To examine the relationship between driving status and demographics, health status, functional status, and mental and psychosocial status. Methods. The Consumer Assessment Study Interview Battery (CAS-IB), administered to 697 community dwelling men and women aged 60 to 106, included instruments to measure health, functional status, and mental and psychosocial status. These variables were compared for three groups based on driving status: those still driving, those who had ceased driving, and those who had never driven. Results. Differences among the three groups were found for age, race, gender, income, education level, home ownership, and living situation. Differences among the three groups were found for many measures of health status and all measures of functional, mental, and psychosocial status. Conclusions. Declines in health, functional ability, and cognition are associated with driving cessation. Availability of alternative forms of transportation, whether supplied by the community, friends, or family, may mitigate additional declines in health, function, and psychosocial status.

The Impact of Roadway Intersection Design on Driving Performance of Young and Senior Adults: Preliminary Results

The Federal Highway Administration (FHWA) proposed highway design guidelines to increase safe driving ability of older drivers, but little empirical evidence exists to support these guidelines. Using kinematics measures from an instrumented vehicle and on-road evaluations, the authors examined the safety effects of improved versus unimproved intersections in older (65–85) and younger (25–45) drivers. Kinematics measures showed that 4 maneuvers had significantly poorer lateral stability for the unimproved conditions, and significantly greater speed for the improved conditions. Behavioral measures showed that drivers had significantly fewer errors for 2 improved left-turn maneuvers, and fewer total errors overall, with older drivers having a higher mean number of errors. These findings suggested that the FHWA guidelines for safe road conditions result in safer driving by older and younger adults.

Strategies and Tools to Enable Safe Mobility for Older Adults

Older adults rely mostly on driving to accomplish their transportation needs. With age-related functional limitations, most notably cognitive decline and dementia, vision impairment, and arthritis, driving may become more challenging. Seniors may need to find ways to maintain or enhance their driving ability or utilize alternate methods of transportation. Based on recent research and product development, a variety of resources are now available to assist rehabilitation specialists and related healthcare professionals in providing programs and information to their older patients. This article provides a comprehensive listing of programs, Web sites, and informational materials to assist older people in remaining safely mobile later in life.

Approaches to Improving Elders' Safe Driving Abilities

SUMMARY The number of older Americans is expected to increase and they will continue to rely on automobiles as their primary mode of transportation. Inadequate alternatives to driving ones own car result in many elders continuing to drive when they can no longer do so safely. Interventions to enable older drivers to drive safely, longer, are essential so that elders remain active participants within their communities. In this paper, current approaches to assist with older driver safety are reviewed, and additional research needs are identified.

Literature Review on Older Adult Gender Differences for Driving Self-regulation and Cessation

Researchers are calling for increased studies with regard to differences between older men and women drivers. This literature review focuses on gender comparisons for self-regulation of driving and driving cessation. We reviewed 20 articles and assigned levels of evidence. Seven studies were level II (eg, prospective cohort) and 13 were level III (eg, cross-sectional). Subsequently, 5 evidence-based recommendations were made to address gender-specific needs of older men and women. Additional research is needed to clarify gender patterns for self-regulation and cessation and increase the level of evidence supporting gender-specific driving interventions.

The Impact of Intersection Design on Simulated Driving Performance of Young and Senior Adults Preliminary Results

The Federal Highway Administration proposed guidelines for highway design to increase the safe-driving ability of older drivers; however, little empirical evidence exists to support these guidelines. This study investigated the effects of improved versus unimproved intersections, using a high-fidelity driving simulator. Kinematics measures and behavioral evaluations were obtained to determine whether driving performance during negotiation of improved intersections was safer for older (65–85 years) and younger (25–45) drivers. Five pairs of intersections were compared. Three of the 5 comparisons indicated significantly greater lateral control stability (as measured by maximum yaw rate) during turns at the improved intersections. This preliminary report is based on data from 19 subjects (5 young and 14 older adults). Despite the small sample size, the findings of this study suggest that some of the Federal Highway Administration guidelines for implementing safe road conditions are helpful in defining intersection characteristics that could lead to safer driving by both older and younger adults. These results may yield critical information for engineers, planners, policymakers, and others involved in the design of roadway systems to enhance safe driving.