Studies Raise Safety Questions about Distractions from Digital Billboards

Roadside billboards have been a part of the American landscape for as long as there have been American roads. Yet today, new technology has updated these icons from static signs to bright, active, frequently-changing message boards that negatively impact traffic safety.

The evidence comes from an extensive review of research showing that digital billboards are more distracting than traditional signs, and that driver attention is particularly captured by changes between advertisements, which typically occur every six or eight seconds. For example:

  • A 2015 study of eighteen digital billboard locations on highways found higher crash rates at sites near digital billboards than those further away. These sites in Florida and Alabama showed a 25 and 29 percent higher crash rate, respectively. A disproportionate number were rear-end and sideswipe collisions, both typical of crashes caused by driver distraction.
  • A 2016 study from the Massachusetts Institute of Technology found that drivers may be unwittingly compelled to look at digital billboards during changes from one advertisement to the next. The report states “it is likely that drivers find it nearly impossible to avoid a glance to digital billboards during switches between advertisements.”
  • In Israel, a 2010 study was performed comparing crashes along a highway before and after billboards were covered (due to a court order) and found a 30-40 percent drop in injury and fatal accidents. A follow-up study (in publication) on the same highway found that such crashes increased by up to 50 percent when the billboards were exposed again.
  • In Denmark, a sophisticated 2013 on-road study showed that “advertising signs affect driver attention to the extent that road safety is compromised.” In 22 percent of test drives, the total glance duration to billboards was two seconds or longer, while in 20 percent of all cases, the “safety buffer” to the vehicle ahead was less than 1.5 seconds.
  • Other recent studies, including an outdoor advertising industry-sponsored study in Australia, and a simulator-based study in South Dakota, have found significant problems with drivers drifting out of their lanes in the vicinity of digital billboards.

Despite this evidence, there is little attention being paid to the problem of distracted driving caused by digital billboards.

It is time to revisit a 2007 action by the Federal Highway Administration (FHWA) that first approved their use. Under this FHWA guidance, billboards changing as frequently as 20,000 times a day were declared to be not “intermittent” as long as they remained static for 4 seconds between display changes. Since this guidance was issued, approximately 7,000 digital billboards have been erected along our highways, often intentionally at the highest traffic and challenging roadway locations where such distractions can pose the greatest risks to safety.

While digital billboards may be succeeding in capturing driver attention, as they are designed to do, they represent a growing threat to traffic safety. In fact, despite the attention given to in-vehicle distractions (such as texting while driving), studies at the University of Massachusetts, Amherst suggest that outside-the-vehicle distractions such as billboards are of greater concern.

The Digital Billboards Subcommittee of the Transportation Research Board will soon issue a series of Research Needs Statements that address some of the most egregious aspects of digital billboards. But given the existing body of evidence, the U.S. Department of Transportation and state agencies should not wait to begin to work with advocates and constituency organizations on new guidance regarding the time, place, and manner of such displays.

The recent focus on the safety problems of in-vehicle driver distraction demonstrates appropriate leadership in response to a critical national problem. Let’s hope that the compelling evidence from numerous studies in the U.S. and abroad about similar threats to traffic safety from digital billboard distractions will spur the federal and state governments to suspend the 2007 FHWA guidance and impose a moratorium on additional digital billboards. Doing so would be appropriate until there is sufficient evidence that restrictions on sign location, message duration, and luminous intensity can and will be imposed on their operation to reduce the risks to traffic safety that have been indicated by so many studies.

(Photo credit: New York Times

Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of The Eno Center for Transportation.

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