With increasing age changes of sensory, motor, and cognitive functions take place. Diseases and medication intake can induce additional functional deficits or can enhance age-related deficits. All these deficits can have an impact on driving and may induce driving problems, errors, and even accidents. The latter are partly registered in the 'Verkehrszentralregister (VZR)'. In order to cope with functional deficits and to continue driving, elderly often activate compensation mechanisms such as the self-restriction to use only well-known routes for driving. Such compensation mechanisms may also be the reason that many of the old drivers that were registered in the VZR were only registered once, i.e. they committed only one VZR-relevant administrative offence. Other reasons for being registered once or rather several times may be differences in driving-relevant competences, personality traits, attitudes, and self-perceptions. The present study investigated in which respect old drivers which were registered either only once or rather several times in the VZR differ with respect to personality traits, driving-relevant cognitive functions and driving behavior. In addition it is investigated whether and which compensation strategies the different groups adopted currently as opposed to earlier in their life (at about 45 years). To this aim two groups of old active drivers (72+, 199 single registered, 200 multiple registered, almost exclusively men) were interviewed by phone concerning driving habits, personality traits, driving-related self-perceptions, and compensation mechanisms during driving. A subsample (N = 96) additionally underwent psychological tests and a driving test in real traffic. The tests embraced some traffic-relevant psychometric tests as well as questionnaires concerning personality traits, self-perceptions, and attitudes. The driving test was conducted on a critical test route in Dortmund; driving behavior was checked by experienced driving instructors using the TRIP-protocol. Concerning compensation strategies most of the respondees stated avoiding critical situations such as driving fatigued or in darkness. Compared to earlier in their life they mentioned as most frequent current strategies more cautious driving and keeping a larger safe distance. In the psychological tests they showed no signs for dementia or depression, and their intelligence was generally high or in normal range. During the driving test about 18% of the participants were rated having doubtful driving skills. The quality of traffic perception and understanding was rated doubtful in 30% and insufficient in about 7%. In the comparison of single vs. multiple VZR registered drivers only few differences were seen: multiple registered drivers had a larger mileage and drove more frequently daily compared to single-registered drivers. Concerning compensation mechanisms there was overall no significant difference between single- and multiple registered seniors. In the single analyses a few group differences emerged. Single-registered seniors avoid currently more critical situations than multiple-registered seniors, which suggests some age-related compensation. However, the numerical differences between the groups were small and only significant in few situations. In particular single-registered seniors avoid driving in darkness currently more than earlier. No group differences were seen concerning personality traits and attitudes towards driving. A clear difference emerged in self-perception: multiple-registered seniors rated their own driving competence as "better than that of younger drivers" more frequently than single-registered seniors. In the psychometric test differences emerged only in the sub-test distractibility of the TAP-M, in which relevant stimuli were presented together with irrelevant ones. Multiple-registered seniors reacted much more slowly to the relevant targets than single-registered seniors. In the driving test in real traffic no group differences were seen. Even though there were single meaningful group differences, the results of the present study provide no consistent evidence for the assumption that multiple-registered seniors have larger sensory, motor or cognitive deficits or different personality traits and self-perceptions than single-registered seniors. Also there was no consistent group difference in compensation strategies and driving performance. The results of the present study hence do not justify increased monitoring or constraints for multiple-registered seniors. Concerning the interpretation of the results it should be considered that the degree of separation of the two groups is presumably rather low. In future studies VZR-registered seniors (preferentially multiple-registered ones) should be compared to nonregistered seniors. Moreover, it can be generally recommended to develop training procedures for older drivers to increase their driving competence and thereby traffic security. (Author/publisher)
Abstract