Study Shows Digital Billboards Do Not Pose Safety Hazard To Drivers

By Christine Kern, contributing writer

Digital Billboards shown to be more effective than their static counterparts

A study by the U.S. Department of Transportation Federal Highway Administration found that digital billboards do not pose a safety risk to passing motorists. The findings are not surprising for those in the industry, but serves to allay fears of consumers and retailers.  Numerous traffic studies and analyses performed in the last couple of decades have come to a similar conclusion.

The report, actually divided into two studies, is officially titled "Driver Visual Behavior In The Presence of Commercial Electronic Variable Message Signs." For the purposes of the studies, the FHA refers to digital billboards as Commercial Electronic Variable Message Signs (CEVMS).  The study was conducted to investigate the effects of CEVMS used for outdoor advertising on driver visual behavior in a roadway driving environment.

The study examined three specific issues:  First, whether CEVMS’ distract drivers’ while driving; second, do glances to CEVMS create a decrease in safety; and finally, do drivers look at CEVMS more than at standard billboards.

The FHA used an eye tracking system to measure driver glances while driving on roadways in the presence of CEVMS, using an eye-tracking camera device mounted in the vehicle. This device was able to track the driver’s eyeball movement and determine if the driver was looking ahead at the roadway or off to the side of the roadway at a static billboard or CEVMS.

The study included drivers in Richmond, Va., and Reading, Pa. The results showed that drivers did look at CEVMS a greater percentage of time than at standard billboards; however, the time spent looking at off-premise advertising was less than 5 percent when the signs were visible to the participants across the two experiments. Long glances at off-premises advertising were not evident. The longest glance at a CEVMS was less than 1.3 seconds and glances greater than 1 second were rare events. The percentage of time that drivers dedicated to the road ahead was not significantly affected by the presence of CEVMS or standard billboards.

Rather, the overall clutter and complexity of the visual scene appeared to be the principal driver of glance time away from the road ahead. This was the case regardless of the presence or absence of off-premise advertising. The results suggest that overall visual complexity of the highway environment needs to be taken into account when considering driver glance behavior.

Glance duration toward digital billboards averaged 0.379 seconds, while glances at static billboards were at 0.335 seconds at both test sites. Both of these measurements fall far below the two-second benchmark, which would constitute a hazard, according to the National Highway Traffic Safety Administration.

In conclusion, the study states, “The results did not provide evidence indicating that CEVMS, as deployed and tested in the two selected cities, were associated with unacceptably long glances away from the road. When dwell times longer than the currently accepted threshold of 2,000 ms [milliseconds] occurred, the road ahead was still in the driver’s field of view. This was the case for both CEVMS and standard billboards.”

This peer-reviewed study reinforces the fact that digital billboards and other digital signage are not hazardous to passing motorists and should encourage retailers to engage in this new medium of advertising.