Cars with keyless ignition systems start with the push of a button and often idle so quietly that drivers sometimes forget to shut off the engine when they’ve reached their destination.

“People are hardwired to think ‘no key in the ignition, the vehicle is off,’” says Clarence Ditlow, executive director for the Center for Auto Safety.

The problem recently led to tragic consequences for one couple in Highland Park, Illinois. They accidentally left the car running in the garage and died at home from carbon monoxide poisoning.

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Safety groups say at least a dozen people have been killed in similar circumstances.

Forgetting to turn off the engine can also lead to other types of hazards. Some drivers have left their cars on in neutral and have been run down and injured by their own rollaway vehicles, according to reports. Older vehicles don’t allow you to remove your key from the ignition unless the car is in park, but a keyless ignition vehicle does.

Tasking automakers to find a fix 

Safety experts say regulators and car manufacturers should step in to find a solution.

“We know that people are going to make mistakes and you shouldn’t die making them,” said Sean Kane, founder and president of Safety Research & Strategies, a research firm specializing in motor vehicle and consumer product safety. “That’s where good engineering comes into play. These problems were engineered out of our cars for years, and now we’ve reintroduced ways of killing and injuring people with problems we solved years ago.”

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Car makers are aware of the problem. As a Lexus representative says on the website, “While your Lexus and its remote key are remarkably sophisticated, they’re not mind-readers. You need to tell them when you’re done using them. I say this because I’ve heard of people parking their car and walking away, all the while having forgotten to turn the engine off!”

Under pressure from consumer groups, the National Highway Traffic Safety Administration proposed new rules in 2011 that would require cars to make a loud, telltale sound if someone tries to exit it while it’s running. Both automakers and consumer groups were unhappy with the rule and it stalled. NHTSA also began a probe into keyless ignition vehicles in 2014.

What drivers can do

If you own a keyless ignition car, there’s no easy solution to remembering to turn it off. You can try taping a note on the dashboard or even on the door between your garage and the inside of your house.

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If you don’t already own a keyless ignition car or you’re buying a new one, look for one with built-in safety features. In its 2015 keyless vehicle models, for example, Ford Motor Company added a feature that kills the ignition if it is left idling.

Daniel S. Levine is an award-winning journalist who heads the Levine Media Group and hosts The Bio Report and RARECast podcasts. He was an editor of The Burrill Report and worked for the Oakland Tribune, Adweek, the San Francisco Business Times and other publications.