A new study,conducted by researchers at the Swedish National Road and Transport Research Institute and funded by the Swedish Transport Administration, concludes that digital billboards attract and hold the gazes of drivers for far longer than a threshold that previous studies have shown to be dangerous.The Swedish government had given temporary authorization to erect digital billboards in 2009.  As a result of this and related studies, however, the government has ordered the removal of all digital billboards.

According to the research, drivers looked at digital billboards significantly longer than at other signs along the same route, in fact, often for more two seconds at a time. Study results were recently published in the journal Traffic Injury Prevention.

The study’s authors noted that it’s not surprising that digital billboards attract greater attention from drivers: the signs are brighter, visible from greater distances and display a constantly-changing series of advertisements. They concluded that digital billboards “have the potential ability to keep up the driver’s curiosity over an extended period of time.” Previous human behavior studies have shown that drivers are hardwired to notice bright, changing lights in their peripheral vision and to anticipate additional motion.

"This study validates what is common sense when it comes to digital billboards," said Mary Tracy, president of Scenic America. "Bright, constantly-changing signs on the side of the road are meant to attract and keep the attention of drivers, and this study confirms that is exactly what they do."

An earlier study by Virginia Tech in 2006 for the National Highway Traffic Safety Administration found that anything that takes a driver’s eyes off the road for more than two seconds greatly increases the risk of a crash. The study also found that nearly 80% of all crashes involved driver inattention just prior to (within 3 seconds) of the crash.

The powerful pull of digital billboards is a topic that flickers across the news media in the U. S. now and then, but not long enough to create a wave of general protest or national regulation, at least not thus far.  In 2010, for example, the New York Times published a story called Driven to Distraction, in which the author noted that digital billboard critics refer to the medium as “television on a stick,” writing that: “These high-tech billboards marry the glow of Times Square with the immediacy of the Internet.”

Some cities have stepped in to ban digital billboards, but not many, and the billboard industry has been vocal in their defense.

The new Swedish study, as well as two other recently completed studies of digital billboards, will be presented during the Annual Meeting of the Transportation Research Board in Washington, DC, on January 16, 2013.