4. Policy and legislation

Wednesday, 23 November, 2022 - 16:50 to 18:20


This presentation will address policy/legislative DUIC issues.

1) Where should we set the limit for the offence related to DUIC? Many countries have established a numerical concentration limit in blood for DUIC, protecting the population health. Some jurisdictions, protecting the driver’s rights, are reluctant to establish a limit as they consider it not defensible; and rely on expert judgement of impairment.

2) Should cannabis impairment be treated equally to alcohol impairment? Jurisdictions have to consider various local factors, to decide on an appropriate local response. Some jurisdictions have set blood/oral fluid concentration limits at levels believed to be similar to acceptable alcohol impairment. Cannabis use combined with alcohol poses a greater threat to road safety. Several countries established higher punishments and lower THC limits for driving after combinations of cannabis and alcohol.

3) Do laws against cannabis in drivers deter drug impaired driving and are they sufficient to change behaviour? Most countries consider punishment as the main form of deterrence, but evidence is sparse. Successful change of drug driving behaviour appears to share two key components: enforcement and increased cultural disapproval. 4) What tools are needed to enforce such laws and how effective are they?

Whatever legislative approach is adopted to DUIC, it has to be enforceable. Enforcement requires some type of biological or behavioural assessment.

Policymakers will need to interpret the scientific findings in line with their local societal and cultural values, to consider what level of risk the jurisdictions are prepared to accept.


Presentation files

23 5B 1650 Brendan Hughes_v1.0.pdf197.16 KBDownload



Part of session