Driving under the influence of psychoactive substances (illicit drugs and certain medicines / licit drugs, in addition to alcohol) increases the risk of crashes and casualties in road transport. Under current regulatory systems, in the EU and most other countries, there are legal limits for alcohol consumption when driving; and roadside breath tests for alcohol have been carried out for some decades. However, legislation regarding enforcement of driving under the influence of drugs has not been unified in Europe. Regarding drugs and medicines, only relatively recently appropriate screening devices have become available — based on saliva samples. About ten years ago it was estimated that between 1% and 5% of motorists were driving under the influence of illicit drugs in Europe; for medicines the estimate was even higher. There has been a lack of knowledge about both the prevalence and increase of the crash/casualty risk caused by the use of various drugs and medicines, particularly the concentration levels from which risk is significantly increased.2 However, relative risk of driving under the influence of psychoactive substances might be comparable to relative risk of driving under the influence of alcohol, say BAC levels between 0.5 and 1.3, depending on the psychoactive substance and the potion/concentration. One of the deliverables in DRUID WP3 is a cost-benefit analysis (CBA), an assessment to what degree (increased) enforcement against driving under the influence of drugs is profitable in economic terms for the society, together with an assessment of which of the existing devices for such enforcement are more profitable. The policy goal of increased enforcement, targeting driving under the influence of psychoactive substances, would be to increase societies? benefits (reduce societal costs) through a deterrence effect that should reduce prevalence and driving under the influence of psychoactive substances, and subsequently reduce the tolls of fatalities and injuries. This implicitly assumes that individual behaviour is affected by the increased presence of police at the roadside and/or the word-of-mouth of acquaintances being tested and/or that the particular driver is tested. (Author/publisher) This document is available at https://www.bast.de/Druid/EN/Home/home_node.html
Abstract