In recent years, the growing number of children and pets left unattended in cars prompted automakers to add rear occupant alert systems in vehicles.
According to the National Highway Traffic Safety Administration, a child dies in a hot car about every nine days. The National Safety Council reports that 38 hot car deaths of children under the age of 15 occur yearly. The nonprofit safety advocacy group also said 10 children died of heatstroke after being left in a vehicle so far in 2022.
Pets, too, get left in hot vehicles. The American Veterinary Medical Association reports that “every year, hundreds of pets die from heat exhaustion” because they get left in hot cars.
We’ll explain how the rear occupant alert systems in vehicles can help you keep your kids and pets safe, how they work, and how to turn them off.
What Is Rear Passenger Alert?
Rear occupant alerts remind drivers to check the back seat. Moreover, many manufacturers offer a type of rear seat reminder system. By the 2025 model year, all vehicles will carry a rear passenger alert system.
Rear passenger reminders can be as simple as a prompt on a car’s infotainment screen reminding the driver to check the back seat before they leave their vehicle. Or, they can be as complex as ultrasonic sensors that detect movement inside a car after the driver turns it off. It may flash the car lights or sound the horn in response.
Why Rear Occupant Alerts are Useful
Leaving a child or a pet unattended in a vehicle is never safe. The inside of a parked car can quickly reach unsafe temperatures, even on a mild day. Consumer Reports testing shows that the interior of a vehicle can reach 105 degrees Fahrenheit — a potentially fatal temperature — after just one hour parked on a 61-degree day.
And while this topic may make you think of kids left in cars by accident, we should note that, in 2020, almost two in five hot car deaths occurred when kids got into vehicles on their own without their parents’ knowledge.
Some hot car deaths can be prevented. According to the safety watchdog group kidsandcars.org, the number of hot car deaths began declining during the last three years.
We’re aware of no studies explaining the decline. But it comes after several years of awareness campaigns aimed at America’s drivers, so they know the danger of leaving a child or a pet in a hot car.
It also comes after a new technology began to appear in cars: rear occupant reminder systems designed to remind or warn drivers that a person or animal may be in the back seat of a parked vehicle.
The systems carry names like Rear Occupant Alert, Rear Seat Reminder, Rear Door Alert, or Rear Passenger Alert.
How Does Rear Occupant Alert Work?
No single standard explains how a rear-seat occupant reminder system works. So, automakers take several approaches to protect children and pets.
Screen Reminders
At the simplest level, some cars prompt the driver to check the back seat for passengers every time they turn off their vehicle.
Door Logic Systems
Most systems available in the 2022 model year use a door-sequencing logic. Onboard computers note when a rear door gets opened before driving. Then, should either of the back doors stay closed after you park the car, the vehicle sounds an audible alert. Also, the vehicle flashes a reminder on the screen or in the driver’s instrument cluster reminding the driver to check for rear-seat passengers.
Motion Detectors
A few cars use a more sophisticated system that detects movement in the rear seat. Hyundai and Kia, for instance, offer a door logic system as standard equipment on almost all of their vehicles. They also provide a more advanced system on some family-friendly vehicles, like the Hyundai Palisade and Kia Telluride. Systems use ultrasonic sensors to detect movement in cars up to 24 hours after being parked and send alerts to the owner’s cell phone.
This approach is rare in the 2022 model year. But it will probably grow more common in future years.
Future Advanced Systems
Manufacturers increasingly fill vehicle cabins with sensors as our cars grow more automated. Driver-attention monitors are growing common. Pointing similar sensors at the rear seats grows more cost-effective every year.
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Also, automakers began researching more advanced rear-occupant detectors. Hyundai, worried that its ultrasonic sensors could miss a sleeping infant covered in heavy blankets, developed a radar-based sensor that can “measure even minute movements of the chest and blood flow of passengers by passing through their clothes.”
Which Cars Offer Rear Seat Reminder Systems?
As recently as the 2020 model year, few cars offered a rear seat reminder system. As the 2022 model year begins, it’s almost easier to list the cars that don’t.
Acura, Buick, Cadillac, Chevrolet, Ford, Genesis, GMC, Honda, Hyundai, Infiniti, Kia, Lincoln, Nissan, Subaru, and Toyota all offer a rear-occupant alert system on most or all of their 2022 vehicles.
Those that don’t yet offer a rear-passenger alert will do so soon.
Is Rear Occupant Alert Mandatory?
Several trade associations represent the auto industry. Many manufacturers are members of more than one. The two largest — the Alliance of Automobile Manufacturers and the Association of Global Automakers — committed to adding a rear-passenger alert system to every car by the 2025 model year.
Now, federal legislation requires rear passenger alert systems. The infrastructure bill signed into law included a provision requiring automakers to install back seat alert systems in all new vehicles. The law gives the Department of Transportation two years to implement the new rule, meaning it will take effect for 2025 model year vehicles.
Can Rear Passenger Warning Be Disabled?
Drivers can disable rear occupant alert systems on most 2022 model year cars. In some cases, it’s a simple switch. In others, it requires paging through several menus on a car’s touchscreen. Consult your car’s owner’s manual for instructions on turning the system off in your own vehicle.
But remember, these systems wouldn’t exist if there weren’t a tragic reason for them. Consider that you may be better off letting it annoy you into checking the back seat often.
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