[Mild dementia and driving ability. Part 2: Assessment and its consequences in practice].

The legal framework and the essentials in traffic and transport psychology and statistics were described in part 1. Safe driving depends on different sensory and mental processes interacting in a complicated manner. Physiological changes and--even more importantly--a variety of diseases result in impaired performance in these functional areas. Moderate to severe dementia certainly means that the person is no longer fit to drive, whereas driving ability may be maintained in mild dementia for some time. There are different approaches and assessment tools, but a single test that could, on its own, answer the question whether a patient with mild dementia is fit to drive does not exist. Driving ability is not only determined by cognitive function. Further assessment of possible risk factors and overall functioning is necessary. If dementia is diagnosed, then the question of fitness to drive must be promptly discussed with the patient because during the course of dementia driving ability will inevitably be lost. The conclusion of the assessment of driving ability must not be pronounced like a verdict, the physician should rather counsel and support the patient and his family on the difficult road towards driving cessation.