That drugs may influence the driving capability has been known for many years, though statistics do not exist. The results of the research are mainly questionnaires of drivers who have been stopped because they are probably driving under the influence of alcohol. A second research group is the group of traffic victims. None of these groups are average drivers. A third way of checking is experimenting in the laboratory to decide whether a drug influences human capabilities. The best way, however, would be to check drivers, who are regular users of drugs. They would have to be controlled in different circumstances in normal traffic. If a medical practitioner prescribes drugs influencing the driving capability, he has to be sure that the patient-driver is clever enough to follow his instructions, or not prescribe them at all. It is also possible to make the patient take a driving test, but the general practitioner remains responsible for the decision whether the patient should or should not drive.
Abstract