Is GM Reviving Seatbelt Interlock?

GM testing a modern take on a once-hated technology.

by Paul A. Eisenstein on May.22, 2014

It has long been viewed as an example of government regulatory excess, as well as technology gone wrong. But four decades after the seatbelt interlock was abandoned amidst a flurry of consumer complaints, is General Motors about to bring it back to life?

The answer is “yes, sort of.” The Detroit automaker plans to test the updated technology – which it calls the Belt Assurance System – on a handful of fleets purchasing a select number of 2015 models. Beyond that, GM just might make the interlock a more widely available option, though there is no indication it would become standard-issue, or part of any revived government mandate.

The original seatbelt interlock was one of the first advanced safety devices ordered into production by the National Highway Traffic Safety Administration. And unlike now, when even modest new systems typically come to market only after years of testing and discussion, the federal agency gave automakers barely six months warning before requiring interlocks on all 1974-model cars.

By then, seatbelts were also required, but usage rates were incredibly low, barely 14%, according to federal statistics. Yet there already was a wealth of data indicating that they provided the best way to stay alive in a crash. So, NHTSA ordered automakers to find a way to make motorists to buckle up. In practice, that meant anyone sitting in the front seat was either cinched in or the vehicle wouldn’t start.

The problem, recalled TheDetroitBureau.com columnist Mike Davis, then a member of the PR team at Ford Motor Co., was that, “The seatbelt interlock was, in my opinion, a good idea whose time simply had not come.”

They were “crude” devices, he added, that often failed to let a vehicle start even if motorists were buckled up. The outcry against interlocks was so severe that NHTSA was quickly forced to lift the mandate. Ironically, it then shifted emphasis to airbags, these so-called “supplemental restraints” ultimately required to be powerful enough to protect unbelted occupants, even a grown male.

That created new problems, as it meant airbags had to be so powerful they could actually cause injuries of their own when they went off.  In turn, the industry raced to fix that new problem, developing “smart” airbags capable of sensing whether someone was actually sitting in a front seat, whether they were a man or a woman, an adult or a child – or even an infant in a safety seat.

And that technology is at the heart of the new GM Belt Assurance System. It knows if someone is sitting up front, and a little tweak can let it also sense if they are buckled up. GM contends the new technology is far more reliable than with the original seatbelt interlocks. And the optional system will still let you start the car – though you won’t be able to shift into drive.

The Belt Assurance System is being unveiled during a month when NHTSA is putting new emphasis on the benefits of seatbelts, which were credited with saving 12,174 lives in 2012.

The agency is also focused on getting more motorists to buckle up – its latest data showing that usage has risen to around 87%, a modest increase over the last decade, but a figure that reflects a stubborn resistance by a small part of the population. The usage rate has been stuck in the 80% range for the past decade, and is still well below the figures from Europe, Japan and many other parts of the world.

A number of states are ramping up their click-it-or-ticket law enforcement. But there is growing interest in adding a technological solution. So, could GM have the answer – ironically, at a time when the maker’s own commitment to safety has come into question as a result of its ongoing recall crisis?

“Customer safety is on the forefront of everything we do. It is essential for the safety of our customers’ and all drivers’ safety to develop the habit of buckling up each and every time they get into their vehicles,” Jeff Boyer, vice president, the maker’s new safety czar, said in a statement. “We continue to support this program by NHTSA to remind our drivers to buckle up each time they start their vehicles while also developing other safety features like our Belt Assurance System.”

The new interlock system will be offered as an option on some of the GM vehicles most often ordered by fleets, notably the Chevrolet Cruze, Colorado and Silverado, as well as the GMC Sierra, starting with the 2015 model-year. If the response is positive, company officials say the technology could be offered more widely, but GM has no plans to make it a standard feature.