Do not speed or drive after drinking
A 1% increase in average speed raises the risk of a fatal crash by about 4%. There is no reassuring “a little is fine” threshold for drinking and driving: risk starts increasing at very low blood-alcohol levels.
What it takes
Free. Driving more slowly may add a few minutes to a journey. The harder part can be declining alcohol at a social meal.
What you may gain
WHO states that each 1% increase in average speed increases fatal-crash risk by 4%. Alcohol-related driving risk starts rising at very low blood-alcohol concentrations.
Context & considerations
The 1% and 4% figures come from crash modeling, not randomized trials. For alcohol, the cited WHO source gives the direction of the association without a numerical effect size. This chapter has not checked the original studies needed to say exactly how much risk rises for a given amount of alcohol.
Research & references
WHO (2025). Road traffic injuries fact sheet. https://www.who.int/news-room/fact-sheets/detail/road-traffic-injuries