Auto Seats Can Kill and Maim

1996:  Kevin Gleason had strapped Sarah, his five-year-old daughter, into the back seat of the family car, as advised by auto safety regulators.  He was in the passenger seat in front of her when their Buick Century was hit from behind by a pickup truck going an estimated 24 miles an hour.  Gleason was thrown forward, then back against his seat.  The impact made his seat back collapse.  He and the seat were launched on top of Sarah, fatally rupturing her heart.

1999:  Tom Comella, an insurance agent and city council president in Highland Heights, OH, was on Interstate 271 on a sunny June morning when his 1992 Chrysler Plymouth Voyager was rear-ended.  His seat back collapsed and he was hurled into the second-row seat, then to the rear of his van, fracturing his cervical spine and damaging his ocular nerve.  At 51 he was paralyzed and blinded for life.  His wife and family tried to take care of him at home, but eventually the father of two teen-age daughters had to move into a nursing home to receive the care he needs.

Isolated cases?  Unfortunately, no.  
 

•	Eddie Jean Curry burned to death in 1997 at age 50, trapped in the back seat of a Mazda when it was hit from behind and the driver's seat collapsed on top of her.
•	When a Jeep Cherokee was rear-ended, its front seat collapsed and the rear gate opened.  A woman riding in front was ejected out the back.  She is a paraplegic for life.
•	A man driving a Nissan Pathfinder was also turned into a paraplegic when his seat back collapsed and turned into a ramp that catapulted him into the back seat; he died from complications.

Danger by the Numbers

Such tragic events are exceptional only because they are not exceptional.  Rear-enders are the most common crashes on the road, and one of the most important safety-components of a vehicle's passenger compartment in such collisions is the seat itself.  It is – or should be – the first line of defense against injury to occupants.

The government does not, however, keep track of how often seats fail in these – or any other – crashes.  Nor does it track how often those failures kill or maim their occupants and those sitting behind them the way it tracks injuries and deaths caused by air bags.  Available data suggest, however, that seat failures are common and, all too often, deadly or crippling.  Everyone in the vehicle is at risk, not only those in the seats that fail, but those sitting behind them as well.

The National Highway Traffic Safety Administration (NHTSA) reports that during 2001, rear-end auto collisions killed 1,747 persons and injured an estimated 488,000.  In 1997, 82 children sitting in rear seats were killed in rear-end crashes, and an estimated 30,000 were injured.  In both cases it is unknown how many of the deaths and injuries involved collapsing front seats.

Analysis of 72 rear-end collisions in which front seats were known to have failed when passengers were sitting behind them showed that the back seat passengers were 25 times more likely to be injured seriously if they were behind a seat that collapsed.  That study, using a government database of tow-away crashes, was conducted for The Los Angeles Times by Keith Friedman, a Santa Barbara, CA, auto safety researcher.  He projected that from 1988 to 1997, 1,800 back-seat passengers, including 400 children, were seriously injured or killed by seat failures.

NHTSA received 390 complaints from consumers about seat failures during 1999 – most likely the tip of a much larger iceberg.  The reported cases accounted for one death and 112 injuries.  Most of the seat failures didn't even happen during crashes, but under normal conditions, such as reaching for pocket change at a tollbooth.

In 1996, Ford disclosed it had been sued 91 times by victims alleging seat failure in Tempo and Topaz sedans.  The Michigan Judge who heard one of those cases observed:  "Even more startling, Ford has defended hundreds of lawsuits involving the same seat in other models."

General Motors has a similar record:  GM Safety Engineer David Viano publicly stated that stronger car seats could prevent 400 deaths and 11,000 serious injuries a year, yet in one five-year period in the late 1980s GM was named in almost 550 lawsuits involving seat failures and received 5,600 owner complaints.  In 1991 alone GM spent $20 million defending seat-collapse lawsuits.
 

Early Warnings

Auto safety engineers and manufacturers have warned about the problem for half a century.  In 1954, the late Derwyn M. Severy, a professor at the Institute for Transportation and Traffic Engineering at the University of California-Los Angeles, conducted some of the first automobile crash tests, demonstrating the need for energy-absorbing seats and head restraints.  It was his testimony during the 1960s that finally led to a federal safety standard requiring even minimal protection.

As early as 1966, an internal GM report acknowledged that "survival is largely dependent upon front seat structures which will maintain passengers in an upright seated position."  The following year, a GM engineer warned that "seat back stiffness should be increased substantially" and cautioned against the "high probability of interference with rear seat occupants" and the "potential hazard¼from the high compressive loads imposed on the cervical spine as the occupant's head is being forced to the rear seat back."
 

The Substandard Standard

Federal Motor Vehicle Safety Standard (FMVSS) 207, which set strength requirements for seating systems in passenger cars, was finally adopted in 1968.  It was extended to vans, trucks and buses in 1972 and has never been changed or improved since.  It requires the seat back to withstand an impact of only 270 foot-pounds.  In his testimony, Severy had urged that seat backs withstand up to 10 times as much.

Incongruously, the safety standard that governs lap and shoulder belts requires that they take up to 6,000 pounds of force without failing, based on scientific human tolerance testing done in the 1950s and 1960s.  In contrast, the seat back standard "is not based on human tolerance testing," says Safety Engineer Mark Pozzi.  "The human body can withstand about twice as much impact from the rear as from the front.  If anything, the seat should be even stronger than the seat belts."  Instead, the standard requires that seats be only 4 to 5 percent as strong.

The standard requires only a static test – hitting the seat with a weight to measure how much force it can take before it collapses.  There is no requirement for testing seat strength either using crash dummies or in real or simulated rear-end crashes, and in the face of resistance from auto manufacturers, NHTSA has backed down from every effort to impose such rules or otherwise strengthen its safety standard.

As Auto Safety Attorney James A. Lowe points out:  "If a 2003 model year vehicle contained seats which would fully collapse¼when occupied by an average size adult male in a 20 mile-per-hour rear impact, resulting in a seat-belted occupant's ramping rearward off the seat and sustaining severe head and neck injuries, there is nothing whatsoever to prevent that vehicle from being sold to the American public.  Seats may be the most dangerous aspect of cars and trucks left; it's time to change that."
 

NHTSA's Awareness Problem

Not that NHTSA hasn't recognized the problem.  It has, repeatedly:
 

•	Agency-funded research at the University of Virginia during the 1990s concluded that tripling seat back resistance would improve simulated-crash results by reducing seat back collapse and subsequent occupant ramping.
•	In 1996, NHTSA admitted its current standard was inadequate.
•	In 1997, it acknowledged that "it may be important to assess the injuries caused by the interaction of rear and front seat occupants due to front-seat collapse. This is especially true with the increased emphasis of placing children in the rear seats" to protect them from detonated air bags.
•	In 1998, it stated:  "Generally, it is acknowledged that the current standard requires inadequate seat strength to ensure that the seat does not fail when a car is subject to a severe rear impact."
•	In 2003, it is still studying the problem.

European car occupants fare a little better than their American counterparts.  The European standard requires that seat backs withstand about 42 percent more force than the U.S. standard.
 

The Easy Fix

The problem is easily fixed, say safety engineers.  Because safety belts are required to withstand much higher forces than seat backs, the strength of existing car seats can be more than tripled for as little as $48 each, using a belt concept available over-the-counter at auto parts stores.  Safety Engineer Todd Saczalski retrofitted his own 1994 Toyota Landcruiser with such belts. The belts are mounted diagonally behind the seats from the floor to the door post to help keep them from collapsing backward in a crash.  

Saczalski also strengthened the front seats of his 1991 Jeep Wrangler by extending a $7 belt behind the seats from roll bar to roll bar, then stretched a $25 tailgate net interwoven with the belt for additional head and neck support.  He has a patent pending on the design.  When he tested the system, he found it "to be stronger than the test equipment could handle."   The seat held at more than 5,000 pounds of force.  Instead, the test load cell gave way and broke.
 

Unequal Seating

Even in America, not all seats are created equal.  Consider two car models made by the same company, Chrysler Corporation.  The front seats of the 1997 Dodge Ram were not exactly "Ram tough."  They could withstand only 605 pounds of force before collapsing.  But the previous year, the seats in the Chrysler Sebring could withstand 3,300 pounds.  

And seven years before that, the 1989 Mercedes 500 SL was even stronger, withstanding  4,575 pounds of pressure.  The Mercedes seats excelled in other ways as well.  They used "belt integrated" seat technology designed to hold occupants in their seats regardless of its position.

The concept had already been tested in one form or another at least 15 years before Mercedes took it to market.  In 1974, while both Ford and GM were themselves testing "belt-integrated" safety seats, the auto industry was simultaneously fighting a federal proposal to require just such designs.
 

The Bogus Hard-Soft Trade-off

A safety concern voiced by NHTSA is that toughening seat backs by making them more rigid may result in more – and more severe – whiplash injuries in rear-end collisions.  

Not until 1995 did the National Accident Sampling System (NASS) start tracking data on seat collapses.  After analyzing the first year and a half of such data from tow-away rear-end collisions, NHTSA reported in 1997 that occupants of seats that failed to stay upright were 5.4 times more likely to be seriously or moderately injured than those whose seats remained upright, but concluded:  

"The data seem to indicate a trade-off in the type and quantity of injuries depending on whether a seat back maintained its initial position or was in a reclined position after the rear crash event. The ¼ (combined moderate and severe) level injury rate increased when the seat back collapsed and the whiplash injury rate increased if the seat back position was maintained."

Almost predictably, NHTSA decided that more study was needed.
 

The 'Catcher's Mitt' Solution

Researchers at GM, however, had already studied the problem throughout the first half of the 1990s.  That research "showed that there was not a design conflict between a rigidized and yielding seat system," wrote GM's Viano.  Seats can be designed both to stay in place without collapsing and to yield and cushion the occupant's body.

Traditional seat backs have stiff structural crossbars inside, often just behind the pelvis.  These limit the cushioning effect of the seat and instead turn it into a ramp.  Even belted occupants can be catapulted up this ramp and into the back seat.

The "catcher's mitt" design solves that problem by removing the crossbars and contouring the seat to help keep the occupant in place.  The seat has a sturdy frame that resists bending, twisting or collapsing, but a "soft" energy-absorbing middle that yields to cradle the torso.  The redesign also puts the head restraint higher and closer to the occupant's head.  Viano cites two benefits:  
 

•	"(T)here is lower force on the upper back early in the crash¼.  The lower the upper back load, the lower the forces causing neck shear, bending and extension."
•	"(T)he head receives full head restraint support before the higher forces occur on the occupant¼.  This allows energy transfer at a time when the head, neck, back and pelvis have uniform¼support."

GM started phasing in what it calls its "high retention" seats in 1995.  Viano reported in his 2003 study that his analysis of data from the Fatal Accident Reporting System showed that the risk of death to drivers and front seat passengers in cars equipped with the improved seats was reduced by 35 percent in rear end crashes that involved two vehicles (excluding heavy trucks).

The BMW 850 had a similarly advanced seating system even eight years earlier, in 1989.  It included:
 

•	Automatic height adjustment of the head restraint and seat belt to assure a proper fit.
•	A clamping device at the upper end of the shoulder harness to reduce the occupant's forward movement in a crash.
•	Belt anchorage points that move with the seat for best belt alignment in all seat positions.
•	An electronic recliner control to eliminate incorrect adjustment.
•	A high-strength seat frame.
•	Seat engineering that absorbs crash energies and prevents "ramping" and "submarining."

The Slow Pace of Progress

Parts of the concept are slowly inching their way into market-production vehicles, primarily those of non-American manufacturers.  The Insurance Institute for Highway Safety reported in October 2002:

Volvo's redesigned seat backs yield in rear-end crashes to reduce the forward acceleration of occupants' torsos.  A specially designed hinge at the bottom of the seat back allows it to move rearward.

Toyota's redesigned seat also allows an occupant's body to sink farther into the seat back during a rear impact.

Saab has introduced active head restraints that move up and toward the head during a rear-end collision, triggered by a sensor in the seat back that responds when the occupant is thrust against the seat.  Some GM and Nissan models are similarly equipped. 
 

The 'Egregious Loophole'

Concludes Safety Engineer Pozzi:  "Over 20 years of field investigation findings clearly establish the serious nature of this continuing defect, the industry and NHTSA's awareness of it, and with very few exceptions, the lack of action to do anything about it.  This is probably among the most egregious, widespread safety defects to be found.  It is not based on science, but solely due to a loophole in the safety standards."

(04/04/03)