Driving performance may be affected by a number of cerebral diseases, in the general population and particularly in the elderly, who exhibit a higher risk of involvement in a road accident. The objective of this research is the investigation of the driving performance – assessed on driving simulator – of drivers with cerebral diseases, especially at unexpected incidents. The basic cerebral diseases considered concern Mild Cognitive Impairment (MCI), Alzheimer’s Disease (AD), and Parkinson’s disease (PD). The driver performance is examined in terms of both traffic and safety parameters. A large experiment is carried out by an interdisciplinary team, in which participants (patients and control population) take part in driving simulator experiment, neurological and neuropsychological tests. The driving performance measures examined include speed, lateral position, reaction time at incidents etc. Preliminary results (39 drivers) confirm that cerebral diseases downgrade the driving performance and particularly the higher impact of PD in relation to MCI/AD and control drivers.