"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% last year, second only to Internet ad sales, they say."
"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."
"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% of overall accidents."
"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."
Until the findings are released (probably in 2009), "the FHWA provides only cursory guidelines on electronic billboards, leaving states and municipalities to decide whether or not they should be permitted."