Responding to the Chicago Tribune Article “Car Seat Tests Reveal Flaws”

FacebooktwittermailFacebooktwittermail

The big news story of the moment comes to us courtesy of the Chicago Tribune.  As you have probably seen by now, they ran a story on Saturday, February 28 titled Car Seat Tests Reveal “Flaws”.    

So, is this overblown, sensationalistic journalism meant to sell more newspapers or is this a real “Houston – we have a problem” issue?  Let’s take a look at what we do know at the moment:  

As part of a research project, infant seats with dummies were secured in the back seats of vehicles that were crash tested as part of the NCAP program.  NCAP stands for New Car Assessment Program. If you’ve heard of “government 5-star ratings,” then you know NCAP. NCAP is part of the National Highway Traffic Safety Administration (NHTSA). 

The purpose of this New Car Assessment Program is to provide consumers with vehicle safety information, primarily front and side crash rating results, to aid consumers in their vehicle purchase decisions. The rating results utilize a star system from 1 to 5 stars, with 5 being the highest.

For frontal crash ratings, dummies representing an average-sized adult are placed in driver and front passenger seats and secured with the vehicle’s seat belts. Vehicles are crashed into a fixed barrier at 35 mph, which is equivalent to a head-on collision between two similar vehicles (vehicles from the same weight class) each moving at 35 mph.  Frontal star ratings indicate the chance of a serious head and chest injury to the driver and right front seat passenger. A serious injury is defined as one requiring immediate hospitalization and may be life threatening.

Normally, carseats are not installed in the back seat of vehicles undergoing NCAP testing.  Instead, carseats and boosters are compliance-tested on a test sled bench at 30 mph to see if they comply with current Federal Motor Vehicle Safety Standards for child restraints.  Considering that sled tests aren’t “real” crashes it makes sense to research how carseats perform in “real” (even if it is standardized) crashes inside actual vehicles.  After all, since you’re going to total the car anyway – why not get the most research bang for your buck by installing some carseats in the back seat.  Not only does this make sense but they’ve been doing this in Europe for years (Euro NCAP) so this isn’t exactly a new idea.     

However, much of the controversy stems from the fact that carseats here in the US are tested on a sled that is set to simulate a 30 mph crash and US NCAP speeds are run at 35 mph.  That is actually a big difference.  I’m not qualified to get into the physics of it all but this is how I’ve heard it explained:  The force in this case changes exponentially, which means the energy goes up with the square of the velocity.  Injury occurs when the change in velocity happens very fast – like when you hit an unmovable object (i.e., a brick wall) at 35 mph.  Restraints and vehicle crumple zones help the occupants inside the vehicle slow down over a longer period of time (remember “riding down the crash”?) which helps reduce the chance and severity of injuries.  When you hit the brakes in your car and gradually slow down from 35 mph to a full stop no one gets hurt because it happens over a long period of time.  The frontal NCAP test produces a high level of occupant compartment decelerations which is very demanding of the restraint systems inside the vehicle. 

Anyhow, the point here is that there is a big difference between a 30 and a 35 mph crash.  Does that mean we shouldn’t test carseats at 35 mph?  Honestly, I don’t have enough information on this to form an opinion one way or another.  However, even the 30 mph FMVSS 213 sled test for carseats is said to be more severe than 97% of real world crashes.  Personally, I haven’t seen the data to back up that claim but for the moment I’ll accept that statement at face value since I don’t have any data that suggests otherwise.  If it’s true, then it makes sense to continue testing carseats at 30 mph.  But that just begs the question – why are we testing vehicles at 35 mph? 

I propose that we either lower the NCAP speed to 30 mph or we increase FMVSS 213 compliance testing speed to 35 mph.  Then we can keep cars and carseats on the same playing field.  And it just makes sense to continue testing carseats in real vehicle crash tests even if that testing is just supplemental for now.  The questions we all need to be asking are:

Are we doing enough?   The 213 sled test just seems so antiquated.  The old (new) bench seat, the lack of front seats, the lack of a floor (on which to secure a foot prop), etc.

Do sled test results tell us anything useful about how a seat will perform in a crash in the “real world”?  If the answer is “not really” then obviously we need to find a better way.   

Is what we’re seeing really a problem?  Are children in the real world being injured because of contact with the front seat?  Are some infant seats really prone to detaching from their bases?  Clearly the old Evenflo Discovery and the old Combi Centre were prone to detaching under certain crash conditions even though there is no evidence that either seat was experiencing problems passing FMVSS 213 standards.  Both seats were recalled last year after the problems became apparent during this “research project”.  

Is there a better way? Ed Whitaker from Combi thinks he found a better way.  Kudos to him for taking this seriously and trying to find a better way to replicate real world crashes without crashing a new vehicle each time.  We need to understand more about this alternate testing method that Combi is now using.

In the end I don’t know what, if anything, will come of this but many parents are going to be concerned and who can blame them?  The scary stuff may be overblown but we don’t know that for sure.  If, because of this article, some parents are no longer comfortable with using an infant seat – that’s fine.  All infants don’t need to use infant carseats.  Most average-size, healthy, full-term newborns can fit well in certain convertible seats.  And I’ve seen instances where a newborn actually fit better in a particular convertible than s/he did in a particular infant seat!  But parents need to know that some convertibles are much better suited to newborns than others.  Here at carseatblog we’re working on a list of convertible seats that tend to fit full-term, average-sized newborns well.  We hope to have this list completed in the next week or two and when it’s done we’ll be sure to post it here. 

Stay tuned for more comments on this article in coming days.  There are just too many issues here to try to cover all the questions, concerns and implications in one blog entry.

4 Comments

  1. Pingback: Transport Canada NCAP Crash Tests October 6, 2009
  2. Pingback: Combi Crash Tests - A Better Way? March 4, 2009
  3. CPSDarren March 2, 2009
  4. canmom March 2, 2009
  5. murphydog77 March 2, 2009
  6. Deborah Stewart March 2, 2009