TRENTON, N.J. – Ashtrays have been disappearing in cars like fins on Cadillacs, and so could smoking while driving in New Jersey, under a measure introduced in the Legislature.

Although the measure faces long odds, it still has smokers incensed and tearing into the idea as a Big Brother intrusion that threatens to take away one of the few places they can enjoy their habit.

“The day a politician wants to tell me I can’t smoke in my car, that’s the day he takes over my lease payments,” said John Cito, a financial planner from Hackensack with a taste for $20 cigars.

Those cigars, pipes, and cigarettes would become no-nos for drivers. Offenders would be stung with a fine of up to $250,under the measure, whose sponsor said it’s designed more to improve highway safety than protect health.

Assemblyman John McKeon, a tobacco opponent whose father died of emphysema, sponsored the legislation. He cites a AAA-sponsored study on driver distractions in which the automobile association found that of 32,000 accidents linked to distraction, 1% were related to smoking.

In the past, Mr. McKeon has also sponsored legislation to prohibit smoking in college dormitory rooms.

His latest measure, co-sponsored by fellow Democrat, Assemblywoman Lorretta Weinberg, comes on the heels of a proposal to ban smoking in bars, restaurants, and the state’s casinos. The smoking-while-driving ban shifts the smoking debate to private property.

The measure, introduced last month just before lawmakers’ summer break, faces some improbable odds for passing.

Some lawmakers may fear the bill is frivolous compared with more pressing issues like taxes, said political analyst David Rebovich.

And there’s this to consider: Traffic safety groups acknowledge motorists now widely ignore the state’s year-old law against using hand-held cell phones, so why would smoking be any different?

Mitchell Sklar of the New Jersey State Association of Chiefs of Police, said police may balk at enforcing such a law. “In general, we’d rather not try to incrementally look at every single behavior and make those a violation,” he said.

Some states, including New Jersey, have considered putting the brakes on smoking while children are in the car. But none has gone for an outright ban on smoking while driving, according to Washington, D.C.-based Action on Smoking and Health, the country’s oldest anti-tobacco organization.

Earlier this year, lawmakers in Germany proposed a ban on smoking while driving as a traffic safety measure.

Smokers, feeling like easy targets, say enough already. They argue they’ve been forced outside office buildings, run off the grounds of public facilities, and asked to pony up more in per-pack excise taxes when states feel a budget squeeze.

A driving ban, said suburban Chicago smoker Garnet Dawn Scheuer, is “completely asinine. It’s unbelievable that they want to try it. People have been smoking in their cars since cars were invented.”

Ms. Scheuer, who tracks anti-smoking measures in the Midwest and Northeast for the New Hampshire-based Smokers Club Incorporated, disputes the distraction argument. “You don’t have to look at a cigarette to light it,” she said.

Mr. Cito, who’s also a member of the cigar society, was more blunt. “They put it all under the ruse of this other crap. It’s government interference. What’s next, my house?” he asked.

Maybe, said Assemblyman McKeon, “If your house was on four wheels and going 70 mph, you’re right, I would.”