In the article the author deals with the issue of investigating subjects who were detained by police after driving a vehicle and giving a positive breath test. The article discusses the problem of insufficient information in the decision of the police authority about taking away a driving licence, in particular the time of detention and the level of alcohol in breath. Furthermore, it discusses difficulties in obtaining relevant data, mainly the documentation from general practitioners. Finally the author mentions unclear role of psychologists in the decision-making process.

Key words: driving licences – positive breath test – assessment of subjects