Anja Knoche

• The DRUID expert consensus established recommendations on how to define limits for psychoactive substance use in traffic. The European DRUID project established a group of experts who are members of national working groups for defining analytical and/or risk thresholds. This group evaluated the results of DRUID, scientific literature and the experience of representatives of several EU Member States and Norway in determining cut-off levels. 1. Cut-offs should be defined for the most frequently used psychoactive substances; 2. In order to achieve compliance of the population towards cut-off regulations, they should be clear and comprehensible, pointing out the risks when used in traffic; 3. Thus, the definition of cut-offs should be based on current scientific knowledge; 4. The lowest substance concentration exerting an effect on driving should be preferred instead of the lowest limit of quantification/ detection; 5. For all psychoactive substances including alcohol, the same risk should be accepted. When a country intends to determine per se cut-off levels, several considerations have to be taken into account. From a scientific point of view, the same risk should be anticipated for all psychoactive substances including alcohol. Nevertheless, every cut-off discussion should address the question if the DRUID approach, to determine risk thresholds equivalent to alcohol limits, is feasible for the respective case.