Zero-tolerance Drinking and Driving Laws: Effectiveness

Are zero-tolerance drinking and driving laws effective in reducing traffic deaths? Brazil implemented a zero tolerance traffic law.


Researchers studied the impact of this law. Data on both traffic deaths and population came from an official source. It was the Brazilian Ministry of Health. Researchers studied the results of zero-tolerance in three of the major capitals in Brazil. They were Rio de Janeiro, Belo Horizonte, and Sao Paulo.

There were no changes in the traffic fatality rates before and after the law in two cities. Those were Rio de Janeiro and Belo Horizonte. But after the law was adopted the rate jumped in Sao Paulo. Yet it had been declining there before the new law.


zero-tolerance drinking and drivingThe researchers concluded that the zero-tolerance law clearly did not reduce alcohol related traffic deaths.

This shows that simple solutions to complex problems may not work. Many other “common sense” policies don’t work either. An example is more severe punishment for those who drive drunk. That may seem logical. Yet it’s the perception of certainty of punishment. Not the severity of punishment. It’s really the certainty that reduces DUI.

And increasing the cost of alcohol might seem helpful. But that has virtually no impact on reducing drunk driving. Heavy drinkers cause most traffic deaths. Higher costs don’t deter them. And most minors who drink and drive don’t buy their alcohol.

Nor is popularity of a program linked with effectiveness. Drug Abuse Resistance Education (DARE) is very popular. Yet research finds it ineffective. Even worse, it’s sometimes even counter productive.


It appears that zero-tolerance drinking and driving laws are probably ineffective.

Zero-tolerance Drinking and Driving Laws


Not all of these are about zero-tolerance drinking and driving laws. But all concern how effective zero-tolerance is.