Concern about drug use and its effect on road traffic safety is increasing globally. While the risks and consequences of alcohol in relation to traffic safety are rather well-researched, the deficiency of information regarding drug use in road traffic is evident. There is not a lot of information available on an international scale concerning the issue of using illegal substances while driving, the relation between concentration of drugs and the risk of a traffic accident, and also about legislative action and prevention of driving under the influence of illicit drugs.

Illicit drugs drastically reduce the ability to participate safely in traffic. The influence of drugs on the driving of an individual differs according to the substance, but they all affect the concentration, judgment and reaction time of the driver. 

Illicit drugs are divided into 4 groups:

  1. 1. Depressors of the central nervous system
  • Narcotic analgesics
  • Anaesthetics
  • Tranquillisers – sedatives
  • Hypnotics – sleep-inducing agents
  1. 2. Antiepileptics
  2. 3. Analeptics
  3. 4. Hallucinogens
  4. 5. Cannabis

In accordance with the severity of the health hazard which may result from their abuse, and how they are used, illicit drugs are classified into groups I, II and III:

  • Group I: plants and substances posing a severe risk to human health due to the serious consequences their use may cause, and which are not used in medicine..
  • Group II: plants and substances posing a severe risk due to the adverse consequences their use may cause and which are used in medicine..
  • Group III: plants and substances posing a medium risk due to the consequences their abuse may cause and which can be used in medicine..
In 2016, 11 participants died in Slovenia in traffic accidents where the responsible person was under the influence of psychoactive substances and illicit drugs, 44 were severely injured, and 68 suffered minor injuries.

The Slovenian Traffic Safety Agency performed an investigation into the use of drugs among Slovenian drivers in 2016, and the results were a cause for concern. Almost every third person interviewed (27%) has taken illicit drugs. 8 % of participants have driven under the influence of drugs. The following drugs are most frequently used by Slovenian drivers: marijuana (89%), followed by cocaine (14%) and amphetamines (10%), then ecstasy (9%), magic mushrooms, LSD and sedatives – each with 7%, heroin (6 %), Valium (apaurin, diazepam) and crack (each 5%), and methadone (4%). Every third person who drove under the influence of drugs had done so regularly (three times a month or more often).