1. Nat. Inst. of Forensic Toxicology, Oslo, Norway
2. Dep. of Forensic Chemistry, Linkøping, Sweden
3. Dep. of Pharmacology, Reykjavik, Iceland
4. Nat. Public Health, Helsinki, Finland
5. Inst. of Forensic Medicine, Copenhagen, Denmark

For more than 40% of the Norwegian cases, the primary suspicion by the police was directed towards drugs, which were detected in more than 70% of these cases. In only 0-3% of the cases from Denmark, Finland and Iceland, drugs were suspected, while the corresponding frequency from Sweden was 17%. However, evidential breath analyses are used for about 3/4 of the Swedish drivers suspected to be under the influence of alcohol, consequently, the Swedish material might be different from the rest.

BAC's below the legal limits were found in 32, 18 and 2% of the Norwegian, Icelandic and Finnish cases, respectively (BAC <0.05%), in 10% of the Danish cases (BAC <0.08%) and in 20% of the Swedish cases (BAC <0.02%). The highest frequencies of drugs were found in the Norwegian and Swedish cases with no alcohol detected (80 - 83%). For cases with BAC's above the legal limits, similar frequencies of drug detections (19 - 22%) were obtained for the five countries. BZD, THC and amphetamine were among the most frequently detected drugs. Our results show that differences between Norway and the other Nordic countries with regard to drugs and driving, are connected to the selection criteria made by the police and probably due to greater focus on drugs combined with driving in Norway.