By Grant Schwab, gschwab@detroitnews.com
Washington — At a time when futuristic vehicle safety features are getting hype and attention from tech enthusiasts, one of the most life-saving areas of innovation is focused on a system first patented in 1962.
Consider the humble seat belt, especially during the busy holiday travel season.
“Beyond the driver, seat belts are the most important safety system in the vehicle,” said Jennifer Morrison, the director of vehicle safety strategy at Mazda North American Operations. “It saves the most lives. It’s the best thing anybody can do when they get in the car.”
The auto industry has made crucial improvements to the familiar device in recent years, including wider adoption of sophisticated crash response systems for rear passenger seat belts. Those software-triggered and pyrotechnic-enabled systems were already saving lives for front-row riders, and their increasingly common deployment in the second row has been a welcome shift for safety advocates.
“We’ve seen tremendous automaker response,” said Joe Young, a spokesperson for the Insurance Institute for Highway Safety.
Rear seat refresh
IIHS is widely regarded as an industry leader in advancing vehicle safety and recently updated one of its key crash tests to boost rear-seat protection. The organization began performing its own crash tests in 1995, which pushed automakers to dramatically improve front-seat safety in the ensuing years.
However, Young explained, that meant the relative risk to passengers shifted to the back seat as automakers focused on safety technology for drivers and shotgun riders.
After observing that trend in vehicle crash data, IIHS launched a new test in 2022 — the “updated moderate overlap front crash test” — to encourage car and truck makers to apply the same level of ingenuity to protecting second-row … passengers.
The test features a vehicle crashing straight into a fixed object at a 40% offset, a more common type of real-world wreck than 100% head-on collisions. The test also newly included a dummy meant to simulate the size of a small woman or a 12-year-old child in the second row behind the driver dummy.
“We’ve seen really solid improvements,” Young said in an interview. “In 2023, about a third of the rated vehicles got a ‘good’ rating in that test. Fast forward to 2025, and we’ve got about half of rated vehicles getting a ‘good’ rating, and 10% or 15% have ‘acceptable’ ratings.”
A significant reason for the improvements has been more widespread inclusion of rear outboard seat belt pretensioners and load-limiters in new vehicles.
Pretensioners are a device that tightens the belt ahead of a collision so passengers are pulled closer into the seat and put into a safer position to receive the impacts both from the crash itself and the vehicle’s air bag. Once a vehicle detects an imminent crash — perhaps through sudden forceful braking — the in-vehicle software sends a signal for the mechanism to fire via a small, controlled explosion.
Load-limiters are devices that provide a mechanical response after a crash to add slack back into the seat belt so it does not stay too rigid and result in cracked ribs or other internal injuries.
Other engineering and design decisions, Young and other vehicle safety experts noted, have also played a role in improving rear seat safety.
Seat geometry and construction, for example, are important for making sure that passengers remain in safer positions during a collision. Tilted seats can prevent riders from jolting too far forward, and cushioning can absorb some of the impact quickly transferred to the vehicle.
Those design decisions can help prevent a dangerous phenomenon known as “submarining,” which is when a vehicle occupant slides forward and the belt goes into the abdomen.
“We need to make sure that that belt stays where it’s supposed to during the crash, which is low across the hips and across the clavicle,” Young said.
The placement of safety belt mounting on the seat itself — rather than the vehicle frame — also improves passenger protection by limiting the transfer of external forces.
Mazda’s safety push
Morrison, who was a crash investigator for the National Transportation Safety Board before joining Mazda, said the Japanese automaker strives to be an industry leader in rear-occupant protection and safety overall. The company has set a goal of having zero fatal crashes from new Mazda vehicles by 2040.
As part of that goal, beginning in the first quarter of 2026, Mazda will become the first automaker to include pretensioners and load-limiters on front and rear seats as a standard safety feature on all of its new U.S. models with at least two rows. (One model, the MX5 Miata, does not have rear seats.)
The company has a smaller footprint in the United States than other major automakers — it hovers around 3% of the U.S. new vehicle market — but has grown revenue significantly over the past decade thanks to investments in its retail presence and its strong safety reputation.
“I think it’s important that you explore new technologies,” Morrison said of more flashy features like self-driving capabilities, lane-centering and adaptive cruise control. “But at the same time, double down on what you already do well, right?”
“Seat belts are so important. And it’s not just buckling up,” she added, alluding to the hidden and sophisticated technology ready to deploy in case of a crash. “Buckling up is like, that’s what you do. That’s what the occupant does. We got the rest. (The seat belt) can do a bunch of stuff you don’t even know about.
“You’ve got an army of 14 devices, essentially. It’s smart enough to know if there’s somebody there and they’re buckled.”
Industry-wide improvement
The nonprofit product rating, safety and advocacy organization Consumer Reports noted stronger rear-seat protection following the launch of the new IIHS test in 2022.
“For model year 2025, in the vehicles that we track (about 353 models), 75% had rear outboard seat belt pretensioners and load-limiters,” said Dr. Emily Thomas, the associate director of auto safety at CR’s Auto Test Center.
“We are definitely seeing more of the technology come standard in new vehicles,” she added in an email.
Thomas also praised Volvo Car AB for its introduction of a multi-adaptive seat belt in front seats for its 2026 EX60 model. The new technology will use sensors to adjust crash response based on passenger characteristics like height, weight and body shape.
Jeep-maker Stellantis NV has added rear seat belt pretensioners and load-limiters to seven of its U.S. models, starting with the Wrangler in 2024. General Motors Co. said the devices are available on “most” of its models, per spokesperson Bill Grotz.
Ford did not respond to a request for comment.
GM also promoted some of its seat belt safety features in a holiday blog post focused on encouraging drivers and passengers to buckle up. The Detroit-based automaker highlighted its “Buckle to Drive” feature that is standard on 2025 and 2026 models and its rear seat belt reminder system that is available on “many” models.
When enabled, the Buckle to Drive system prevents drivers from shifting out of the park position for 20 seconds or until their seat belt is buckled. The feature applies to front seat passengers on some models, too.
That feature is meant to combat a sad reality of vehicle crashes.
“We know from research,” said Young, the IIHS spokesperson, “that seat belt reminders that are persistent and are loud actually do help get a lot of people to put on their safety belts. That’s really important because — it’s pretty wild — if you look at the real-world data, even though most people do belt up, still about half of the people that die in passenger vehicle crashes weren’t wearing their seat belts.”
Young noted that the average age of a vehicle on U.S. roads is about 12 years, meaning millions of cars and trucks do not have the sensors and alert systems that have become more common. But they do have seat belts.
“If we could just get everyone to belt up, it would be amazing. It would really cut down on the number of people who are dying,” he said.
Young also made a plea for drivers and passengers to be especially careful and patient while traveling to see family and friends during the holiday season.
“As people are hitting the road, I think my message is to do what they can as individuals to make the roads safer,” he said. “And that’s to belt up, watch their speed and avoid impairment and distraction.”
