The organisation says that lack of consistency in enforcement from one country to another, as well as outdated and cumbersome testing procedures in some countries, sends the wrong messages to individuals who remain prepared to risk their own lives – and those of others – by driving after using drugs.

'Some countries have not faced the fact that there are far too many drug drivers on the road,' said TISPOL president Roar Skjelbred Larsen. 'Both Belgium and Spain have recently introduced efficient screening systems based on saliva testing, which saves time and allows many more drivers to be controlled.

'We urge governments to learn from the good practice that is in place, so that consistent, robust enforcement and wider random testing can provide the necessary back-up to drug-driving education programmes,' he added.