Asses­sing older dri­vers’ fit­ness to drive

Older drivers’ fitness to drive is an emotional issue for drivers themselves as well as a much discussed topic in the public, especially after serious accidents caused by older drivers.

The issue raised is whether or not older driver’s fitness to drive should be assessed from certain age onwards.

However, so far it is not clear whether or not mandatory age-based population screenings of older driver fitness to drive improve traffic safety. Therefore, the UDV (German Insurers Accident Research) commissioned two studies: 

Study 1: Assessment of international age-based population screenings for fitness to drive

This study investigated the effectiveness of internal age-based population screenings for fitness to drive for prevention traffic accidents. Evaluation studies already existing were systematically reviewed. The results is that there is no positive safety benefit of these screenings, neither or the older drivers themselves, nor for the general public.

Study 2: Assessment of older drivers’ fitness based on their individual psychophysical fitness

The second study investigated whether older driver’s individual psychophysical fitness predicts their fitness to drive. First, we analysed the sensory, cognitive and motoric performance of older drivers using psychological tests. Second, we observed their driving performance in a test drive or in a driving simulator. Finally we related older drivers’ tests scores with their driving performance.

Results:

• There are considerable age-related deteriorations in older drivers’ psychophysical fitness.
• These age-related deteriorations are gradual. Effects become manifest mostly at age 75 and older.
• Psychophysical abilities change differently. By tendency there is a linear decline for sensory functions. Cognitive functions exhibit a sudden decline.
• The variability of older drivers’ psychophysical fitness is very high.
• There are only few differences between older and middle-aged drivers in real traffic. For example older drivers hardly carry out a shoulder check especially in demanding traffic situations.
• There are somewhat more differences between older and middle-aged drivers in a driving simulation task. Older drivers made more mistakes in unexpected driving situations, such as a pedestrian crossing the lane who was hidden by a parked car and only visible after stepping out on the lane.
• Predicting driving performance with older drivers’ psychophysical fitness was only partially successful. No psychophysical test was able to consistently predict driving performance across driving situations.

Conclusions:

In summary the results do not justify a mandatory driver population screening with neither age nor psychophysical tests as valid indicators.