The debate about the effects of alcohol and cannabis on road safety is often an emotional one. But what do scientific studies say? A recent analysis confirms this: Alcohol is significantly riskier than cannabis in road traffic. Why is this the case and what are the consequences?
Alcohol vs cannabis: the facts

1.1 Alcohol impairs driving skills more
Alcohol leads to a significant deterioration in reaction time, coordination and judgment. The risk of accidents increases significantly from 0.5 per mille. Higher concentrations lead to:
- Severely restricted perception (tunnel vision)
- Overestimating one’s own abilities
- Increased willingness to take risks
- Studies show that drunk drivers cause more serious accidents than drivers under the influence of cannabis.
1.2 Cannabis has other mechanisms of action
Cannabis affects driving differently than alcohol:
- Slower reaction time, but no aggressive driving style
- More cautious driving behavior (drivers often compensate by driving slower)
- No direct link to fatal accidents (in contrast to alcohol)
- Nevertheless, driving under the influence of cannabis is not risk-free – the danger increases especially in combination with alcohol.
Why is alcohol often trivialized?
Despite the clear risks, alcohol in road traffic is often socially tolerated. The reasons for this are:
- Cultural acceptance (alcohol consumption is widespread)
- Underestimating the dangers (“One more beer is fine”)
- Lack of information about the actual risks
Political and legal consequences
Should legislation take greater account of the different risks of alcohol and cannabis? Currently, similarly harsh penalties often apply, although the risks are not the same. Possible approaches:
- More differentiated limits for cannabis
- Stronger controls on drink-driving
- More awareness campaigns about the specific risks
Conclusion
Alcohol is demonstrably more dangerous in road traffic than cannabis. Nevertheless, the topic is often discussed in an unobjective manner. An evidence-based approach could help to develop more sensible laws and prevention measures.
Source: https://norml.org/news/2025/05/01/analysis-alcohol-poses-a-greater-threat-to-road-safety-than-cannabis/