Durham should be careful about changing its rules to let electronic billboards go up, the city-county planning department said this week.

"This is a very complicated regulatory arena," planner Julia Mullen told the Joint City-County Planning Committee Wednesday.

That committee is composed of city council members, county commissioners, the Durham Planning Commission chairman and the city-county planning director.

Mullen reported on the city's current ordinance and concerns raised by highway signs that can outshine the sun and change their messages in a matter of seconds.

Among those concerns are the signs' effect on highway safety. Some research indicates that electronic -- or "digital" -- billboards are a traffic hazard, she said, and several more studies are under way.

"These safety studies are pending, and waiting for the outcomes is advisable," Mullen said.

Last year, Fairway Outdoor Advertising, which owns 46 of the 89 "permitted" billboards in Durham County, asked that it be allowed it to move some of its signs, upgrade some and convert some to digital operation.

The company withdrew its request after the City-County Planning Committee suggested it test public opinion first.

Fairway is doing just that, said Durham attorney Patrick Byker, who represents the company.

"Talking to a wide range of community groups to find what their input is, and that's why we haven't submitted something formally," he said.

"We're enjoying getting input from our citizens, and we're looking forward to submitting something later this spring."

Durham's present ordinance, in effect, outlaws billboards in most locations. Those billboards that do stand along Durham's roads went up before the ban took effect in 1984.

Assistant City Attorney Karen Sindelar said last week that amending the law to grant Fairway's wishes could essentially re-legalize billboards, undoing the ordinance Durham has spent more than $1 million defending against billboard-industry lawsuits.

Legal effects were not part of Mullen's presentation. Rather, she confined it to digital billboards.

"We do anticipate digital billboards would be part of any text amendment that's proposed," she said; and those have raised the most objections in the neighborhood e-mail conversations about any ordinance change.

Mullen said the planning department had consulted information from the American Planning Association, the UNC Highway Safety Research Center, the nonprofit Scenic America, the Outdoor Advertising Association of America, Fairway, news articles and the state Department of Transportation.

Among the planning report's points:

* Fairway's billboards now produce about $2,600 in county tax revenue; switching some to digital "would still not generate significant revenue"

* Local government cannot require the signs to carry public-service messages

* Changing the ordinance could be construed by some citizens as an inappropriate endorsement of products or services such as alcohol and "adult" merchandise

* Digital billboards could be found to violate the federal Highway Beautification Act

* Allowing digital billboards while safety studies are pending could expose Durham to liability for accidents

* Full sunlight reaches about 6,500 "nits," a measure of direct light; a digital billboard can reach 10,000 nits;

* Anything that distracts a driver's eyes from the road for more than two seconds, in an urban environment, significantly increases the chances of a wreck.

Commissioner Ellen Reckhow, the planning committee's chairwoman, indicated Fairway would have an opportunity to make its case if it submits a formal request.

"That would be great," Byker said.

Raleigh, Chapel Hill, Cary and Morrisville have billboard ordinances similar to Durham's, but committee members said several other North Carolina cities allow digital billboards, among them Charlotte, Greensboro, Asheville and Wilmington.

Los Angeles, Mullen said, imposed a three-month moratorium on billboards in December in response to angered residents; and a statewide two-year moratorium, recognizing safety concerns, is pending in the California legislature.