[Mild dementia and driving ability. Part 1: Fundamentals].

Physiological changes, but most of all diseases, affect driving ability in old age, whereby cognitive and mental performance plays an important part. Impaired health and feeling of unease while driving are the main reasons for driving cessation in the elderly. The causes of crashes and crash development show typical features compared to younger drivers. In the assessment of accident frequency and crash risk, sophisticated analyses are necessary. A person with moderate to severe dementia is certainly no longer fit to drive, whereas driving ability may be maintained in mild dementia for some time. In part 2, comprehensive information on the practice of assessment and judgement of driving ability is provided.