How are rollovers survivable?

Posted on April 19, 2008 by Law Office of D. Hardison Wood

One of the obstacles victims of rollover accidents face is the stereotype that rollovers are inherently dangerous.  This isn't usually, and certainly not always, the case.  Rollovers tend to be very survivable, especially when compared to a high speed side impact collision or a head on collision.   The forces at play are dissipated along several axes in a rollover, whereas in side impact and head on collisions, the forces tend to operate in straight lines and along one axis.

Not to say rollovers aren't deadly.  There are approximately 10,000 deaths in the US alone per year due to rollovers.  Most of these are single vehicle accidents.  Roof crush and occupant ejection are the single biggest factors in these fatalities. 

Occupant ejection is minimized by the use of safety belts equipped with pretensioners (these devices were first introduced in 1981).  When searching for a new vehicle, especially an SUV or light truck, make sure to ask if its seat belts are equipped with pretensioners as these will decrease the likelihood of occupant ejection in a rollover event.

Roof crush, on the other hand, is not so easily fixed.  Maintaining occupant survival space is the first goal of successful engineering, yet too many of today's SUVs do a lousy job of this.  Look at this example of a simulated Ford Explorer rollover.  They will roll it twice, not unlike what would happen if the vehicle rolled at highway speeds.  Make sure you watch the full video.  On the first roll, you'll see the passenger side leads, and maintains its survival space, while the driver's side already shows sign of deadly intrusion.  On the second roll, you'll see there is no survival space left on the driver's side.


There is no way the driver walks away from this.  On the flip, we'll show you another test where a rollover seems hardly violent at all.
 

This is the same test run on the Explorer, two rolls, but here on a Volvo XC 90.  What the full video, and notice how survival space remains completely intact.


Both the driver and the passenger walk away from this.  Thanks to Xprts LLC and CIR for making these tests publicly available.  You can learn more about these tests, and how simple modifications can improve existing technology to save lives here.
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Roof Crush

Posted on August 27, 2007 by Law Office of D. Hardison Wood

A new study relates that strength of a car's roof to its ability to prevent  serious injury  in a rollover crash.

A new report from the University of Alabama has studied Ford's own internal crash test data and concluded that the strength of a vehicle's roof is absolutely critical in preventing death or serious injury in the event of a rollover incident. Read More.


Ford has resisted this common sense conclusion for decades in its defense of hundreds of crashworthiness lawsuits.  In these suits, Ford argues that serious injury and death are not a function of roof strength, but instead these injuries a function of violent rollovers.  Implicitly, and sometimes explicitly, championing the position that rollovers are so violent no roof can help, no matter how strong.

I'm hopeful independent analysis such as the above study will continue to resist this overly literal and self-interested interpretation of rollover accidents.  No one disputes that a rollover can generate strong g-forces inside the cabin.  But vans rollover and SUVs rollover... period.  Strong roofs keep heads, necks, and other vital body parts inside and safe from the those deadly gs.  Just ask the many NASCAR drivers who rollover their cars at speeds in excess of 150mph and walk away from these crashes with little more than a scratch.

No reason, other than profit and price, that you can't have the same.

But this brings up another point.  The argument Ford has been using for so long is  flawed on another, more legalistic level.  The inquiry Ford is making preeminent when they argue this way is: could the occupant survive this very deadly crash?

That's a very narrow way of looking of products liability.  Classically, the inquiry is opposed to the above.  That is to say, the focus of the issue is not whether or not there's any way to prevent the damage, but rather whether the risk of the harm justifies the cost of amelioration.

Put another way, in classic legal tort theory we presuppose that you can build a crashworthy vehicle.  And in almost all cases this is true.  Only the most violent, least likely, esoteric collision situations are "un"engineerable.  If that isn't true folks, we are in some trouble cause it means our engineers have hit the wall of innovation.

After we presuppose crashworthiness, we then ask: is the cost of making  the vehicle crashworthy in balance with the potential harm should it remain uncrashworthy.

With around 5,000 SUV deaths alone per year, I would argue we haven't quite hit the cost threshold just yet.  And more importantly, I think most people faced with the question framed in this broad context  would come to the same conclusion.
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Car Seats Sometimes Don't Help

Posted on July 12, 2007 by Law Office of D. Hardison Wood

This is a very unfortunate story, and our thoughts and  prayers go out to this child's family. 

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