KEYPORT, N.J. - The number of places where smokers can legally light up in New Jersey has gotten even smaller, with new laws banning smoking in most of Six Flags Great Adventure in Jackson and inside cars with children in Keyport.

Keyport, a Shore community in Monmouth County, is the first town in the state to restrict smoking in automobiles.

"We're not trying to use the power of the motor-vehicle system to punish people into behaving the way we want them to," Mayor Robert Bergen said. "This ordinance is really intended to be a positive public policy statement about the need to take care of our kids."

Audrey Silk, founder of a New York smokers' rights group, said Keyport was overstepping its authority.

"A car is an extension of your personal property," said Silk, whose group, NYC Clash (Citizens Lobbying Against Smoker Harassment), is also active in New Jersey. "For the government to regulate what you can do in your own private property, everybody should be afraid of that."

The ordinance, which the Borough Council approved Tuesday, sets a $75 fine for smokers who light up in vehicles when anyone 17 or younger is present. The violation is a secondary offense, meaning police need another reason to stop the vehicle.

Public and legislative sentiment has swung dramatically against smoking in the Garden State. A year ago, New Jersey passed a ban prohibiting smoking in public places and workplaces. It exempted Atlantic City's 11 casinos, fearing a crucial component of the state's tourism industry would be hurt. But the City Council passed an ordinance that took effect April 15 to limit smoking to no more than 25 percent of the casino.

Restrictions like Keyport's are being debated nationwide, too. A measure pending in California would outlaw smoking in cars when children are present, and Arkansas and Louisiana have passed similar laws.

Keyport's ordinance gives police wide discretion to let violators off with a warning, Bergen said. He said he expected the borough would not issue more than a handful of summonses each year.

Gina Nasta, who waited until her daughter had gotten out of the car outside Keyport Central School yesterday morning before lighting a cigarette, said she thought the law was a good idea.

"I never smoke in the car when there are kids," she said. "I don't think anybody should."

Central School mother Michelle Parks said she, too, supported the ordinance. Her children, ages 7 and 9, got her to quit smoking several years ago.

"Kids don't have a choice. Why would you subject them to something toxic?" she asked.

Great Adventure, a sprawling complex that includes a ride park, a water park and a safari park, has restricted smoking to designated areas since the season started April 2.

The park has ejected 93 violators and refused to refund the cost of their admission, which can run up to $84.99.

The park asked the Jackson Township Council to enact an ordinance backing up its policy with fines of $250 for a first offense, $500 for a second offense, and $1,000 for subsequent offenses. The council approved the ordinance Tuesday.