Recent UK accident statistics show that older drivers (60 years+) have more casualty accidents compared to other age groups per mile driven, and drivers aged 70 and above have dramatically more accidents per mile driven. In recent years attention has been given to the role dementia may play in older drivers' accidents. This paper is based on a literature review of dementia and driving carried out by TRL on behalf of the Department of the Environment, Transport and the Regions. Research into dementia and driving suggests that although dementia can reduce safety, people in the early stages of dementia can be relatively safe drivers. Therefore, there may be a need to introduce standard screening tests to identify drivers suspected of having a dementia who are unsafe to drive, and to allow those who are safe to continue driving. Tests of cognitive ability and driving performance are possibilities. However, the former have low reliability and validity and should not be used alone to determine fitness to drive. Simulator and on-road assessments of driving have better reliability. However, there are few examples where they have been validated against objective safety measures such as accidents. Problems of reliability and validity are compounded by methodological problems of research in this area. There is a need for further research to clarify the relationship between cognitive test performance, driving performance and objective measures of driving safety. (Author/publisher)
Abstract