In essence, it's a 50-foot plasma TV on a 75-foot pole, set above the madding traffic pouring out of downtown Atlanta.
A slice of Times Square off Peachtree Street, the sign, which can be seen half a mile away, uses hockey players to hawk airline tickets, with images rotating every eight seconds. It's one of more than 500 digital billboards hovering over US highways.
The problem is that it didn't just catch the eye of drivers. As billboard companies scurried to erect more around the city, the Atlanta City Council in January enacted a temporary ban on the signs. It's one in a string of communities from Concord, N.H., to Eden Prairie, Minn., that has raised questions about the safety of TVs in the sky.
Now, the Federal Highway Administration is putting $150,000 toward a study to try to settle the issue as the century-old debate over billboard ethics moves from one of highway beauty to one of highway safety.
"Clearly, today's technologically savvy drivers ... might drive by such things, unfazed, thinking 'It's a big TV on a stick. Who cares?' " says Doug Hecox, a spokesman for the Federal Highway Administration (FHWA). "But whether the risks are the same across all age groups is unknown."
For now, the FHWA provides only cursory guidelines on electronic billboards, leaving states and municipalities to decide whether or not they should be permitted, Mr. Hecox says.
For guidance, most planners look to a 1996 FHWA ruling that permitted "tri-view" signs – mechanical signs where triangular panels turn over to display new images every few seconds. No state allows moving images on highway billboards. However, regulations are generally more lax for "on-premises" signs, like those located on the grounds of car dealers and sporting arenas, that can show video clips and animation – even if they are located next to interstates.
Digital billboards cost about $500,000 to put up. Billboard companies like them because they can charge premium rates for an effective medium that can show many ads on the same pole, media analysts say. In fact, outdoor advertising sales grew about 12 percent last year, second only to Internet ad sales, they say.
"There is growth there, not just for electronic billboards, but also for plain old paper billboards in the right locations," says Neal Weinstock, president of Weinstock Media Analysis in New York.
In communities, digital billboards have advantages compared with static ones, says Heidi Kershaw, communications manager for the Outdoor Advertising Association of America (OAAA) in Washington.
•In the Twin Cities, a test of an Amber Alert system on digital billboards last week netted the arrest of an estranged father who had kidnapped his daughter.
•Albuquerque, N.M., is employing digital ads to flash a series of public service messages that include urging water conservation.
•In Cleveland, the new technology served as a peace offering between the city and advertisers. The industry has promised to use a fewer number of digital billboards in return for taking down numerous smaller signs that officials said were eyesores.
But critics say the very reason the signs appeal to advertisers is the reason they pose a danger on the roadways: The billboards are designed to distract. A study on driver behavior released by the National Highway Traffic Safety Administration last April showed that distractions in which a driver spent more than two seconds looking elsewhere than the road contributed to 22 percent of overall accidents.
"People need to know these enormous TV sets are going to pop up along highways.... It's going to be a significant safety issue for the country," says Kevin Fry, president of Scenic America, a group in Washington that lobbies to keep highways clear of clutter.
For its part, the OAAA cites a 2004 study by the Virginia Tech Transportation Institute, indicating that driver behavior doesn't change measurably in the presence of attention-getting billboards.
Many experts, too, doubt whether the new billboards will stand out.
"These electronic billboards create no more of a traffic safety hazard than a vinyl-wrap board with a stationary image," says Alan Weinstein, a land-use expert at Cleveland-Marshall College of Law in Cleveland.
So far, the battle over such billboards is playing out at the local level. Dozens of municipalities – including the Twin Cities, Concord, N.H., and Atlanta – have imposed moratoriums to study them further. Billboard companies have filed several lawsuits in the hope of weakening or nullifying local ordinances by citing the First Amendment right to free speech.
"If a city wants to decide that they want to be like Times Square, that's one thing, but [outdoor advertisers] are by no means trying to limit the location of their signs to those communities," says John Baker, a land-use attorney in Minneapolis.
The study on the safety of electronic billboards – which may not be completed until 2009 – will help states and municipalities deal with the kinds of new technologies not foreseen by Congress in the Federal Highway Beautification Act of 1965, the FHWA says.
Today, some 450,000 vinyl-clad billboards are located over US roadways, and some analysts have predicted that perhaps 70,000 of those could be retrofitted to digital in the next five to 10 years.