Don't speed and don't drive after drinking
- High value
- Evidence B
- Buys life
- Free
- Takes minutes
- Some willpower
In plain words
For every 1% increase in average speed, the chance of a fatal crash rises by about 4%. There is no safe level of alcohol where “a little is fine.” Risk starts rising even when the alcohol concentration in the blood is still very low.
- Cost
-
Free. Driving slower costs a few extra minutes a trip. The hard part is drinking less at a dinner table.
- What you get
-
The World Health Organization (WHO) says that for every 1% increase in average speed, the risk of a crash that kills rises by 4%. The risk of drunk driving starts to rise from a very low blood alcohol concentration.
- Notes
-
The 1% and 4% figures for speed and death are estimated from crash models, not from randomized trials. For drunk driving, WHO gives only the direction, not a number. The question of how much risk rises per drink has not been checked against the original literature in this section.
- Evidence grade
- B : Supported by research but without a precise number, or based on small or single studies.
- Sources
-
- WHO (2025). Road traffic injuries fact sheet. https://www.who.int/news-room/fact-sheets/detail/road-traffic-injuries
Translated from the Chinese original. Original book, section 1, tip 9. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer