These highway safety signs cause more crashes than they prevent

Every year, more than 1.35 million people are killed in car wrecks.

In an effort to bring those numbers down, some highway authorities are reminding drivers of the stakes. For a decade, nearly 900 digital signs on Texas highways have sent safety messages to drivers. Most of time, these signs convey a generic message, like “DON’T DRINK AND DRIVE.” For one week per month, they also include a morbid statistic: the number of deaths on Texas roads so far that year.

Most U.S. states have similar signs. A new analysis finds they may not have the intended effect. In a surprising paper published Thursday in the peer-reviewed journal Science, researchers find that signs communicating the number of on-the-road fatalities are associated with a slight increase in accidents — 1.35 percent — on stretches of highway downstream of the sign.