As part of the project, an online self-report questionnaire for drivers age 65+ was designed, which can help sensitize the target group to age and illness-related capability losses relevant for road safety. One aim of the questionnaire is to provide older drivers with advice on how to improve their driving safety, with the advice and feedback being tailored to the individual reports on problems and difficulties the users are already aware of . Furthermore, answering the questionnaire and being informed about relevant competencies by the feedback is supposed to hone older drivers abilities to realistically self-assess their own driving competence and sensitize them to the topic of mobility at higher age. The questionnaire was constructed based on the findings of a comprehensive literature search about driving competence in old age and on existing selfevaluation test procedures. In addition to possible deficits in the areas of visual acuity, cognition and motor skills, the questionnaire also deals with the self-efficacy and compensation measures. The use the questionnaire as a psychometricallyquantitatively oriented measuring instrument for specific competencies was not an intended goal of the project, nor is such an application of the instrument advised. The questionnaire was used in two empirical studies. First, a representative survey was carried out with a total of 608 car drivers, a total of 406 of whom belonged to the target group of the questionnaire (65 years or older). The remaining 202 persons were between 35 and 55 years old and were included in the study to compare the response behaviour of older drivers with that of the younger subsample. The representative survey showed a tendency to low approval rates to the items of the questionnaire which focus on deficits. For the majority of participants, reported deficits were few and far between. This response pattern was the same across all age groups. Furthermore, no major differences between age groups could be identified. Since the same response patterns could also be replicated in the following Study 2, it can be assumed that the patterns found, and the lack of age differences, are not primarily caused by a selection bias. Both results can rather be explained by the fact that most aspects of driving competence are genuinely hard to realistically self-assess, and that observable and therefore reportable problems in everyday driving can only occur if a deficit is present that is not balanced out by compensational efforts. The aim of the second study was to validate the self-evaluation reports from the questionnaire based on a clinical assessment and a one-hour driving behaviour test in which the driving competence of 40 older study participants was evaluated by two trained driving instructors using school grades based on the number of mistakes. The correlations between all three data sources were calculated, i.e. the correlations between the self-evaluation test and both external criteria and the correlations between clinical assessment and the driving behaviour test. Only very small and for the most part non-significant correlations were found between all three surveys. Based on the clinical results and the driving behaviour test it could be concluded that the sample could be classified as average to slightly above average in overall performance and did not contain a larger number of extremely unfit drivers, but that the results, in turn, cannot only be attributed to a sample with too little variance. Possible reasons for the lack of correlations were discussed, among others, in the form of the fundamental problem that different deficits are of varying salience and measurability depending on the form of data collection (self-evaluation report vs. laboratory measurement vs. external observation in the driving behaviour test). One major insight gained by the empirical study is the fact that neither the conducted objective clinical measures of capability nor the self-assesment of the drivers could be used to reliably predict the real driving performance. The missing correlation between self-report and driving performance as shown in the on-road driving test can be interpreted as a sign that drivers oftentimes are not assessing their own driving ability in a realistic manner. This underlines the relevance of the main goal of the questionnaire as an educational tool intended to sensitize drivers for possible losses of their driving ability. Another important result was found with the fact that in the driving behaviour test, in less than 50% of all situations the necessary shoulder check was performed, and that only a fraction of these cases could be explained by a clinically measured mobility impairment of head and shoulder. Qualitative comments made by the participants further led to the conclusion that oftentimes the omission of necessary shoulder checks was rather caused by a lack of motivation or acceptance of the importance of shoulder checks. Regarding to the further measures, the necessary steps for the implementation, publication and distribution of the questionnaire are discussed first. In addition, opportunities for further research in connection with the self-evaluation test are pointed out. (Author/publisher)
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