09Evidence B

Don’t speed or drive after drinking

On average, for every 1% increase in speed, the chance of a fatal crash rises by roughly 4%. There is no “safe” level of alcohol consumption when it comes to driving; even very low blood alcohol concentrations already raise the risk of accidents.

Cost

There’s no direct cost. Driving a bit slower adds just a f…

Benefit

According to the World Health Organization (WHO), a 1% rise in average speed translates to a 4% increase in th…

Cost

There’s no direct cost. Driving a bit slower adds just a few minutes to each trip. The hard part is drinking less at social gatherings.

Benefit

According to the World Health Organization (WHO), a 1% rise in average speed translates to a 4% increase in the likelihood of fatal crashes. The risk of a fatal crash also climbs steadily as blood alcohol concentration rises, even at very low levels.

Original sources

WHO (2025). Road traffic injuries fact sheet. https://www.who.int/news-room/fact-sheets/detail/road-traffic-injuries

Open source link
Book note

The 1% and 4% figures linking speed to fatalities come from accident modeling rather than controlled trials. For alcohol and driving, WHO only provides a general trend without specific numerical values. This section does not verify any original research on exactly how much drinking raises risk.

My note