The problem with road safety signs

Driving the news: New York City announced this week it would spend $4 million on a campaign to try to curb dangerous driving behaviors like speeding. At the center of the campaign are billboards like the one pictured above, showing a gruesome traffic accident.

• The catch: Such visuals can end up causing even more distraction.

The big picture: A recent study of traffic signs in Texas found that interventions that "seize people's attention" (the study looked at signs showing the number of recent local traffic fatalities) can end up causing more deaths.

• What they found: "In-your-face," "sobering," negatively framed messages seize too much attention (i.e., are too salient), interfering with drivers' ability to respond to changes in traffic conditions.
• By the numbers: Weeks when the signs were displayed saw a 4.5% increase in the number of crashes over 10 kilometers (6.2 miles) after seeing a sign. That works out to an extra 16 fatalities per year, just in Texas.

The bottom line: Driving slowly and safely is a habit, not something that people should be consciously thinking about. A shocking sign is more likely to just end up distracting drivers than it is to cause a lasting change in behavior.