By James R. Heale
Imagine a seat that flimsy in the third row, inches from the rear glass, as in today's sport-utility vehicles and car-SUV crossover models. The kids are buckled up back there, you're stopped at a light - and a drunk doesn't notice and rear-ends you at 30 or 40 or 50 miles an hour. The result is frightening to contemplate.
Chances of that happening are growing fast because third-row seats have become a must-have feature in millions of vehicles. To meet customer demand, third rows are being squeezed wholesale into both SUVs and crossovers barely long enough to accommodate them, leaving mere inches between the seat and the back of the vehicle.
Distance isn't the only criterion for judging the safety of third seats; seat strength and design are key. But every one of those seats is governed by a 32-year-old federal strength and safety standard that won't be changed for at least a year.
Birth of a Trend
Watershed year for third-row seats was 1997: Dodge offered midsize, midprice Durango with a third row, and Mercedes-Benz put one in its upscale ML SUV.
Previously, third rows were for minivans and big SUVs.
Now, when third-row seats are offered, they're taken. For example, 96% of Durangos had three rows last year.
If seating is the question, aren't minivans the answer? "I hate minivans. I'd never in a million years have a minivan," says Linda Steinberg of St. Louis, speaking for thousands of minivan defectors.
But "when people started
turning away from minivans, they wanted SUVs to do everything their minivans
did," says George Peterson of consultant AutoPacific.
"The third row is pretty vulnerable to rear-enders - like about twice as dangerous" as other rows, says safety consultant Mike Brownlee, formerly in charge of defect investigations and rules compliance for the National Highway Traffic Safety Administration (NHTSA). As more third-row seats hit the market, injuries and deaths will increase, he predicts.
Seat safety has been under fire for more than a decade. The proliferation of third-row seats, mainly meant for kids, gives the complaints new vigor.
"A lawn chair could pass" the NHTSA minimums, says Kevin Calcagnie, a Newport Beach, Calif., lawyer who has sued car companies over seat-related injuries.
Ford Motor's director of safety research, Priya Prasad, won't buy that, but he did provide the big-guy-squirming example of what could overwhelm a seat no stronger than the feds require.
13 Years and Not Done
NHTSA plans to propose seat-standard upgrades this summer - 13 years after the agency began its official rule-change process in response to requests from safety experts. It'll take at least a year to collect public and industry comments and fashion a new regulation. The delay, NHTSA says, is proof of how complex the issue is, rather than evidence of foot-dragging.
Here's the dangerous problem: In a rear crash, the seat back - regardless of which row - acts as the restraint system, just as the safety belt and air bag do in a front crash. If a seat back is so rigid that it stays upright in a violent rear-ender, the stiff seat slams its passenger forward at the moment of impact. Then the passenger snaps backward against the stiff seat as the struck vehicle halts. Severe whiplash can result.
If, on the other hand, the seat is so yielding that it'll absorb lots of the crash force, the seat back bends far enough backward that the passenger could fly out into whatever's behind - solid glass or a tailgate, in the case of third-row seats.
The bounce-back from a yielding seat also can cause whiplash. Plus, it takes close to 3 feet of space for a yielding seat to lay back fully. A third row gets that much space only in big SUVs, such as Chevrolet Suburbans.
The sweet spot is somewhere between very stiff and fully yielding, but nobody's quite sure where. There's no generally accepted crash-test dummy to measure rear impact forces, and no universal rear-crash test to measure seat safety.
There were 2.3 million rear collisions in 2000, according to the latest-available federal statistics. That was 21.7% of all crashes. There were 2,980 fatal rear-end wrecks in 2000, 6.2% of all fatal collisions.
The worst thing about a rear-ender might be the driver's helplessness.
"A rear-end collision is one you don't control. Somebody drives into you while you're sitting at a light or something. In front, I can see what's coming and try to avoid it," says Matthew Bernstein. He lives in Manhattan, drives a crossover SUV with three rows, and calls it "a little nerve-racking" because his kids are so close to the back.
A decade before third-row seats became a must-have feature in SUVs and crossovers, they were merely a practical accessory in minivans. Now there are millions of minivans on the road with third-row seats, enough to generate reliable accident data.
When a minivan with a third-row occupant is hit from behind, the occupant is killed half the time, according to a Ford Motor analysis.
It's lucky, then, that third rows are infrequently occupied - just 1% to 2% of the time, according to accident statistics.
But when somebody is back there, it's usually a child. Adults won't even fit many of the latest third-row designs. Kids are least likely to be properly buckled up, studies show, and correct use of the safety belt is key to surviving rear crashes, safety experts note. Compounding the danger, today's third rows are pretty close to the point of rear impact.
For example, GM's Buick Rendezvous, a crossover SUV based on a minivan, has just 8 inches between the third-row seat back and the tailgate glass. Ford's Explorer SUV has 13 inches. Honda's Acura MDX has about a foot, depending on how the seat's adjusted. Suzuki's XL-7 small SUV has about 13 inches of clearance, depending on the adjustment.
An extraordinarily well-designed seat can help make up for lack of crush space. But there's more agreement on what makes a good cup holder than what makes a crash-worthy seat.
"There is no litmus test. It's largely judgmental," says Bob Lange, General Motors' executive director of vehicle crash-worthiness. "There's no single evaluation one can run that says, 'Yup, you got it.' There's a lot more art to it. It's like Goldilocks - it has to be just right."
And "just right" means different things to different automakers.
BMW Chairman Helmut Panke, for instance, says that his marketing people have been lobbying for an optional third seat for the BMW X-5 crossover SUV. But Panke says he hasn't seen a design that he believes is safe, because the seat would be so close to the rear of the vehicle.
Rival brand Volvo, on the other hand, has a slightly bigger crossover SUV called XC90 coming late this year with a third-row seat, and insists it is safe. "It was tempting to put the third row farther back, but we have to have the crush space for a high-speed (rear-end) crash," says Hans Wikman, XC90 project director.
"Whether there's 1 foot or 3 feet in the rear, it comes down to the design," says Frank Paluch, chief engineer at American Honda's research and development operation.
No Universal Design
In addition to disagreement on how far back third-row seats safely can be placed, there's no universal seat-design standard.
Ford's Prasad says most models in the U.S. market have settled on about triple the NHTSA standard. NHTSA requires a seat back to withstand 3,300 inch-pounds of force, a measure of pressure equivalent to what 3,300 pounds could exert at the end of a one-inch lever, or 1 pound could exert at the end a 3,300-inch lever, or any combination of those that multiplies to 3,300.
In Prasad's earlier example, a hefty driver pushing backward exerts more force than that. A safety consultant's proposal to NHTSA 13 years ago suggested 56,000 inch-pounds.
"Everybody has migrated to about 10,000 inch-pounds. The seat should not break if you are leaning against it entering the car, or if you go into your hip pocket for your wallet," Prasad says.
Lange says GM's standard is "multiple times" the federal standard. Honda says its seats are less than twice the federal standard, but safe because its vehicles dissipate crash forces well.
Those are the closest to real numbers that automakers provide. Car companies say their seats are safe and exceed federal standards, but won't disclose the seat-strength numbers to prove it.
NHTSA began looking into modifying its seat-safety regulations in 1989 after separate petitions from safety consultants Edward Harkey and Kenneth Saczalski, both focusing on seat backs.
NHTSA's official position on its long-running process: "There is genuine debate in the technical literature regarding the risks and benefits of more-rigid seat backs vs. those that yield, and we must ensure that any changes to the standard are cost-beneficial without producing other safety problems. ... NHTSA intends to issue a proposed upgrade to the seat back standard this summer."
The agency, in separate actions, is toughening head-restraint regulations and fuel-system strength rules before revising the seat standards. Proper head restraints will minimize whiplash threats posed by stiffer seats, NHTSA believes. And fuel systems that must not leak after 50-mph rear-enders, instead of 30-mph now, will minimize fires, dangerous to people trapped inside because of flimsy seats.
Safety consultant Brownlee, the former NHTSA official, says head restraints are key. "The company line has been that you have to have forgiving seats. But the trick is you have to have the seats and the head restraints acting in concert, and then you're OK. The whole whiplash thing is a red herring," he contends.
Without even an imperfect index of seat safety, consumers have little but the chorus from car companies: "Trust us; seats are safe."
Does that mean that people in the back seat of GM's Buick Rendezvous, only inches from the back glass, are as safe in a rear-end crash as those in the third row of GM's Chevy Suburban, three feet from the back?
"Well," says GM's Lange, "maybe."
USA Today March 1, 2002
Personally, I had always considered vehicle safety a high priority. It had never occurred to me that these popular third row seats posed a potential threat. However, it appears quite obvious that this is a huge potential area of concern.
I can't tell you how many patients I have seen in my own practice who were just sitting at a light and had some car run right into their backend.
Life is all about balancing risks and resources and some may not have any practical options. However, if you do have some flexibility in the way you use your vehicles it would clearly seem wise to not use the third row on any of these vehicles unless it was absolutely mandatory.
I was impressed that BMW's marketing department considered sought a third seat but BMW's president elected not to based on safety considerations. I admire integrity in leadership.