What is really great about this article is that is was in a trade magazine - Media Buyer Planner dated January 11th 2007. It includes links to other articles concerning billboards and billboard companies mentioned in the article.

Digital Billboards Hazardous, Say Driver Safety Researchers

Digital billboards, the obvious next big wave in outdoor advertising, may be facing a battle, with safety experts saying that the new billboards add yet another distraction for drivers.

While there are currently only about 400 digital billboards across the country, there may be as many as 4,000 within 10 years, according to the Outdoor Advertising Association of America, writes The New York Times.

Digital billboards can change messages more frequently and easily than traditional billboards, thus bringing in more revenue for the billboard company and providing better targeting for the advertisers.

The billboard industry claims that the signs are not dangerous. Though the image looks like a TV image, it does not move (except to change messages from one advertiser to another).
But driving safety researchers say there isn’t enough research to know for sure, and that digital signs may tax a driver’s awareness more than static signs.

Deanna Singhal, research associate at the Traffic Injury Research Foundation, a driving safety group in Ottawa, believes that not only do digital billboards keep drivers’ eyes away from the road more, but that they are also more “cognitively demanding.”

A study commissioned by the Federal Highway Administration has recommended more research into whether the signs present risks to drivers, and the federal government has also allotted $150,000 for a study of digital signage.

Clear Channel Outdoor has created digital networks in six cities, while Lamar Advertising is converting about 28 traditional billboards to digital signs each month.

“Changeable signage is very much a part of the outdoor landscape as we move forward,” Jodi Senese, executive vp of marketing for CBS Outdoor. Although CBS Outdoor does not yet offer digital signs, Senese says they offer creativity, flexibility and targetability, “which was really never an option for out-of-home advertising.”

Billboard companies must obtain permits from local governments to convert traditional billboards to digital, and can expect to be asked to negotiate on everything from a quota on the signs to a limit to the brightness of the images.