With increasing age often changes in sensory, cognitive, and motor abilities occur. The probability of developing medical conditions and taking medication increases. All these factors can influence the ability to drive. To assess the fitness-to-drive an on-road assessment is usually considered as the gold standard, but it also has certain disadvantages (e.g., dependence on traffic and weather conditions; occurrence of dangerous situations). Here, driving simulators can offer an alternative. In the study at hand an innovative driving route for a simulator assessment of fitness-to-drive in the elderly was tested. The study was conducted in the fixed-based driving simulator at BASt and performance of elderly and middle-aged drivers was compared. Before the driving test, drivers had to undergo a special familiarization training to reduce simulator sickness. The course was designed to meet the requirements for on-road driving tests in real traffic. It comprised representative, moderately difficult scenarios of rural roads, urban traffic, and highways. Driving competence was assessed using the Standardized Application for Fitness-to-Drive Evaluations (S.A.F.E.) by trained observers. During the entire drive driving parameters like speed, lateral position, headway to other vehicles, number of lane changes, and size of accepted gaps at intersections were continuously recorded by the simulation software. In addition computer-based tests of cognitive skills related to driving were conducted. Elderly persons performed worse on the computerbased tests than the control group. Only very few participants did not complete the driving route due to simulator sickness. With respect to fitness-todrive elderly drivers were rated slightly worse by the observers than middle-aged drivers. Also the total number of driving errors was higher in the group of the elderly. With respect to driving errors, the standard deviation and the range of the total number of driving errors were higher in the group of the elderly drivers. This points to a high interindividual variability in older age. The fact that in the group of the elderly chronological age could not predict the total number of driving errors underlines that driving fitness has to be judged always on an individual basis. The study furthermore showed that by conducting a simulator familiarization training and using the here evaluated driving route for the simulator assessment the prevalence of simulator sickness can be kept low. This procedure is well suitable for research on fitness-to-drive among elderly drivers. (Author/publisher)
Abstract