Annette Meng

Cognitive screening of older drivers does not produce safety benefits

Although screening policies for older drivers based on chronological age are widely used in many countries, previous research has shown that increasing age does not cause higher crash rates and that consequently, chronological age per se is at best only a weak predictor of safe driving performance. Previous research on age-based mandatory screening of older drivers has not been able to demonstrate any safety benefits from screening measures. The present study is a population-based evaluation of the safety effects that the introduction of the cognitive test as an age-based screening tool has had in Denmark. The primary data used came from the Danish road accident register. The present study compared the number of fatal accidents before and after the implementation of screening for cognitive impairment. There were two main findings. First, there was no statistically significant difference in the number of older drivers involved in fatal accidents before and after the implementation of the screening process, indicating that the screening had no effect on the safety of older drivers. Second, there was a significant increase in the number of unprotected older (but not younger) road users who were killed between the two periods of observation, suggesting that the screening process produced a modal shift among older persons from driving to unprotected, significantly less safe modes of transportation. As a consequence, the number of fatalities in this group increased. Older driver screening is an example of a political measure that intuitively makes sense, but fails to produce the desired benefits. On the contrary, on a system level, it decreases the overall safety and is connected to various direct and indirect costs.

Cognitive problems, self-rated changes in driving skills, driving-related discomfort and self-regulation of driving in old drivers

Ageing in general is associated with functional decline that may have an adverse effect on driving. Nevertheless, older drivers have been found to show good judgement and to self-regulate their driving, which may enable them to continue driving safely despite functional decline. The process of the self-monitoring of driving ability and the awareness of functional decline, and its association with the self-regulation of driving is, however, not fully understood. The aim of the present study was to examine the perceived changes in driving skills, the discomfort experienced in driving, and the self-regulation of driving as measured by the avoidance of certain driving situations by older drivers with different levels of self-rated cognitive problems. Eight hundred and forty Danish drivers aged 75-95 completed a structured telephone interview. The results showed that the recognition of cognitive problems was associated with an experience of improvement in higher level driving skills but also of a decline in lower level driving skills. Moreover, cognitive problems recognised by drivers were associated with discomfort in, and avoidance of, driving situations. Finally, a linear relationship between discomfort in driving and avoidance was found and this tended to be stronger for drivers recognising cognitive problems. The results indicate that older drivers who recognise problems with cognitive functions display good self-assessment of changes in their driving skills. In addition, the results suggest that driving-related discomfort is an important factor affecting the self-regulation of driving. Finally, the findings indicate that driving-related discomfort functions as an indirect self-monitoring of driving ability and may contribute to the safe driving performance of Danish older drivers.

Older Drivers’ Reasons for Reducing the Overall Amount of Their Driving and for Avoiding Selected Driving Situations

Structured telephone interviews were conducted with 840 older drivers to explore their reasons for self-regulating their driving. The main reason for reduced driving was having fewer activities to drive to, and for avoidance of driving situations, reasons also included not liking or feeling insecure about driving in the situation. The lower-functioning participants, but still only a minority, were more likely to indicate decline in vision and reaction time as reasons for avoidance. Women were more likely to indicate lack of confidence as a reason for avoidance. The results suggest that the reduction in driving and avoidance of driving situations are separate types of self-regulatory behavior; that self-regulation of driving is an automatic process, in which older drivers are not aware that they are compensating for functional loss; and that it is important to acknowledge gender differences when designing interventions aimed at enhancing safe mobility.