In a packed Supreme Court chamber on Tuesday, the state’s justices considered the question of whether North Carolina’s Map Act amounts to an exercise of the state’s police power — much like local zoning laws — or instead constitutes eminent domain, requiring just compensation to landowners whose property is included in highway corridors drawn by the N.C. Department of Transportation.

The Map Act allows the DOT to file maps of future highway corridors with local officials and block construction permits from being issued on the affected property for up to three years. The justices Tuesday heard an appeal from DOT of last year’s ruling by a unanimous Court of Appeals that sided with a group of Forsyth County landowners. The appeals court ruled that when the state invoked the Map Act, it was using eminent domain powers, requiring property owners to be compensated.

While the case before the state Supreme Court deals with property owners in Forsyth County, the Map Act also has been used in Guilford, Wake, Cleveland, Cumberland, and Pender counties. The outcome of the case could determine whether the DOT has to pay hundreds of millions of dollars in compensation to as many as 1,500 property owners statewide.

“The Department of Transportation contends that the Map Act is a regulatory enactment within the proper scope of state police power,” said John Maddrey, the state’s solicitor general, who was making the case for the DOT. “It is designed to coordinate future road projects with current and future uses … in and around municipalities and rural areas.”

Justices peppered Maddrey with questions.

“How would you characterize the benefit or the purpose of the Map Act?” Justice Paul Newby asked. “Isn’t it to set in place the value of the property … by restricting improvements or subdivisions to keep the ultimate cost of the property at a particular level?”

“That is certainly one aspect or element of the rationale behind the Map Act,” Maddrey responded. “But public purpose or benefit can be broadly described as coordinating future road projects and current and future land uses. It has similarities to a county or city adopting long-range planning document, a zoning ordinance that talks about land uses in the future.”

“Isn’t it actually designed to ultimately acquire property, not just to regulate it?” Justice Robin Hudson asked.

“The acquisition of the property comes when the Department of Transportation proceeds with a project,” Maddrey said.

“Isn’t that ultimately the goal?” Hudson asked.

“Ultimately, if the project is approved to go forward by the Board of Transportation, then there will be acquisition of property,” Maddrey said. The map is set in advance of that decision, he added.

Matthew Bryant, arguing for the property owners, said that the Map Act imposes development restrictions on property in highway corridors for the purpose of controlling prices.

“That is a taking requiring just compensation,” Bryant said.

Bryant pointed out the difference between government police and regulatory powers, such as with zoning laws, and eminent domain powers.

“There is a difference — a constitutional difference — between telling the owners you can’t build too close to his other neighbor’s house and telling that same owner you can’t build that there because someday in the unannounced future at some unknown time the state is going to want that property,” Bryant said.

Bryant said that some of the property owners’ fight over the property with the state has gone on for 20 years.

“They’re asking Mr. Kirby to wait until he’s dead,” Bryant said, referring to Gene Kirby, one of the property owners.

Newby questioned if the DOT’s action could be considered a temporary taking, such as when a construction crew uses property for a temporary period of time.

“There’s nothing temporary about this,” Bryant responded. “It is a permanent taking. We call them that. … Everyone knows that the road is coming.”

Bryant said that the Map Act also allows the DOT to delay condemning property, which reduces the cost to taxpayers.

The justices made no ruling Tuesday. Typically, the high court issues opinions several months after hearing oral arguments.