Drugged driving, a review based on the experience in Norway.

Since 1959, the Norwegian Road Traffic Act has prohibited driving under the influence of drugs other than alcohol. On suspicion, the police request a clinical examination from any driver, as well as blood analyses for illegal and prescribed drugs affecting driving performance. During the last few years, there has been a marked increase in the number of drivers suspected of be influenced by drugs (1983, n = 900; 1995, n = 3329). The most commonly detected drugs are tetrahydrocannabinol, amphetamine, benzodiazepines and opiates. Multi-drug use is frequently found (> 60%). The occurrence of amphetamine (1991, n = 216; 1995, n = 937) and heroin (1991, n = 19; 1995, n = 172) has increased considerably. The frequency of drugged drivers apprehended in roadside traffic appears to be at least 10-fold higher in Norway than most other countries. This is probably mainly due to differences between national road traffic acts and the level of attention to the problem, and not to national differences in the prevalence of drugged driving.