NEW CITY, N.Y. (AP) – Smokers will have to stop lighting up on the road if they’re riding with children in Rockland County, under a newly approved law that a county official has called a first for the state.

Dr. Jeffrey Oppenheim, a neurosurgeon and the president of the county Board of Health, said Rockland is the only county in the state that has approved such a law. Similar measures have been enacted in Keyport, N.J., Bangor, Maine, Arkansas, and Puerto Rico.

County Executive C. Scott Vanderhoef signed the measure into law Friday. Vanderhoef said he had considered vetoing the measure out of reluctance to regulate behavior, but protecting children from secondhand smoke outweighed other concerns.

“Generally speaking, government should be careful when attempting to intervene in the conduct or behavior of individuals in private settings,” Vanderhoef said in a statement. But, he added, “The health and well-being of innocent children is the overarching goal of our society.”

The law, which got the county Legislature’s approval in May, will take effect when filed with the New York secretary of state. Violators will face a fine of up to $100 for a first offense and up to $250 for each subsequent violation. The law applies to cars with anyone under 18 present.

Critics have called Rockland County’s law an invasion of privacy and a violation of personal liberties, and they have questioned the practicality of enforcing it.

Supporters have noted that the state already regulates drivers’ behavior in other ways – through laws that require seat belts and child safety seats, punish drunken driving and barring drivers from using hand-held cell phones behind the wheel, for instance.

Vanderhoef acknowledged that enforcing the new smoking law could be difficult, but he suggested that its mere existence would deter people from smoking with children in their cars.

AP-ES-06-16-07 1206EDT