Car Accidents May Be More Likely After Traffic Safety Message Boards: Study

Although state and local traffic officials have been increasingly using prominent message boards along U.S. highways to convey safety messages in recent years, the findings of a new study suggests these road safety messages may actually be contributing to thousands of car accidents every year.

In a report published last month in the journal Science, researchers with the European Research Council outlined the impact of car crash fatality and safety messages used through Texas, indicating that the number of crashes increased within miles of the signs. As a result, the study warns that such traffic safety “nudges” need to be carefully designed and positioned to avoid backfiring.

Researchers examined data on all auto accidents occurring in Texas between January 1, 2010, and December 31, 2017, to investigate the effects of a safety campaign launched by the Texas Department of Transportation, where messages displaying roadway fatality statistics would be shown for one week each month. The safety messages were spread out across the state’s highways on 880 dynamic message signs (DMS).

The information gathered was used to estimate if there was any difference in the number of auto accidents during the weeks prior to the fatality messages and the period during and after the activation. The study’s authors focused on the areas around the DMSs, particularly the road segments after the signs during their activation. The results indicated that the intent of the safety messages was not matching their actual impact. In fact, the signs appeared to be doing the exact opposite.

According to the data, the weeks where fatality messages were displayed saw an increase in auto accidents of 4.5% in the area roughly six miles beyond the DMS where the sign was displayed. This uptick in accidents would be comparable to increasing the speed limit on those roadways by 3 to 5 miles per hour or reducing the number of highway troopers by 6% to 14%, thus limiting their presence and ability to quell speeding.

The findings suggest that in-your-face road safety messages may actually be contributing to nearly 17,000 car accidents per year in the United States.

The problem appears to be the inherent properties of behavioral interventions, which are supposed to be attention-grabbing at a time when the person viewing can make the desired action. Though the safety campaign was designed to promote safe driving by displaying signs that demonstrated the costs of reckless driving in the number of lives lost; the fatality messages on Texas roadways have proven to be more of a distraction that led to drivers focusing more on the message or the anxiety the message induces than the road ahead, other drivers and possible road hazards.

It is suspected that the Texas campaign potentially causes an additional 2,600 crashes and 16 fatalities statewide per year. Across the U.S., 28 states have employed behavioral interventions in a similar fashion. As of yet, there have been no other studies examining the effectiveness of these campaigns in other states.