An increasing number of vehicles come with virtually indestructible glass windows designed to keep passengers from being thrown from their vehicles in the event of a crash or rollover. The glass, which is made of the same materials as windshields, also provides a quieter ride.
But new research from AAA highlights a potential downside, too: The growing use of laminated glass to encase most of the passenger compartment could also hinder a driver’s escape if the vehicle catches fire or enters a body of water and begins to sink.
The organization raised the concerns as part of its research into the efficacy of vehicle escape tools on the market.
AAA, which randomly selected six escape tools found online for its tests, said most were able to break the tempered glass still found on many vehicles. But none was able to break the laminated glass, AAA testing found. The escape tools also included recessed blades to cut through a seat belt safely, and those worked fine in each model, the organization said. AAA did not identify the tools by brand.
The research comes as automobile manufacturers, in response to federal safety standards, have increased the use of laminated glass in passenger vehicles. Tempered glass, which is heated or formulated in such a way that it’s stronger than regular glass, is generally used for front and rear passenger windows. Laminated glass, which is formed from layers of tempered glass and sheets of plastic sandwiched between, is even stronger.
About a third of all 2018 models use side windows made of laminated glass now, a 67 percent increase over the past 10 years, AAA said. That could complicate efforts to get out of a car quickly in the relatively rare threat of vehicle fire or submersion.
(AAA’s report is careful to note that crashes and rollovers pose a much greater risk to motorists than car fires or becoming submerged in water. Nearly 7,200 people died and nearly 172,000 people were injured in an estimated 222,700 rollover crashes in 2017. More than 21,000 people were thrown from vehicles during a crash. In that same year, however, about 1,874 people died in crashes involving vehicles that caught fire or became submerged.)
To conduct the tests, AAA selected six escape tools at random from those available online. All of them had a metal striker and a sturdy, recessed blade intended to cut through a seat belt. Three were basically small hammers with a pointed metal striking surface that a person would have to swing at the window. The other three designs featured a spring-loaded metal striker that allows the person to place the tool against the glass and trigger the striker.
Researchers found the seat belt-cutting devices all did what they were supposed to do, in times ranging from a little more than a second to nearly 23 seconds. But AAA had mixed results with the glass-breaking tools, with the spring-loaded tools performing best. Researchers, using a mechanical arm to deliver consistent blows of a force consistent with the human arm, found that two of the three hammers failed to break even the tempered glass.
Although it’s possible to break the laminated windows, it’s much harder, AAA said. Researchers said motorists would be wise to find out what kind of windows are in their vehicles, especially since some vehicles have different types of glass at different locations in the vehicle and not all of them are laminated.
AAA also created a video demonstration of the tools’ use — conducted with staff from the Orange County Fire Rescue Department in Florida — that shows how to use the tools in a sinking car with tempered-glass windows.
“To improve safety, more vehicles are being equipped with laminated side windows — but a majority also have at least one window made of tempered glass,” John Nielsen, managing director of Automotive Engineering and Repair for AAA, said in a written statement. “Our research found that generally vehicle escape tools can be effective in an emergency, but only if drivers know what type of side windows they have, otherwise they could waste precious seconds trying to break glass that will not shatter.”