IIHS to Launch Roof-Strength Ratings

Rollover Over the past few years, there has been great debate between automakers and the government about beefing up roof-strength standards on cars and SUVs. Now, the Insurance Institute for Highway Safety has announced it will add a new rating to its array of crash tests specifically to rate roof strength. The new Roof Strength Rating will measure the amount of force placed on a roof to crush it 5 inches. The ratings will follow IIHS’ current scale of Good, Acceptable, Marginal and Poor. IIHS will begin the tests this spring and make them part of cars’ eligibility for Top Safety Pick status for all 2010 vehicles.

This is a significant step in the battle over roof strength. While rollover accidents make up only 3% of all accidents, they account for nearly one-third of all traffic fatalities, leading to 10,000 deaths annually. The National Highway Traffic Safety Administration is raising its standards for roof strength as well, to two and a half times the weight of the vehicle. IIHS’ top score would be four times the weight of the vehicle.

“We’ll be using the same evaluation method as the federal government,” IIHS spokesman Russ Rader said. He said he also expects the current number of Top Safety Picks, 72, to go down significantly once the agency rolls out the new tests.

Rader says the four-times-the-vehicle-weight rating was chosen because of IIHS research that showed it would lead to a 50% reduction in fatalities in single-car rollover accidents versus the current one-and-a-half rating, and a 35% reduction compared to NHTSA’s new rating of two and a half.

Consumers will be able to find the new scores alongside current crash test ratings for front, side and rear impacts on the IIHS website.  

The government has done some preliminary tests on certain models, and you can find which ones will meet or exceed new IIHS standards below. Manufacturers eager to say these new standards will cost too much or add too much weight to vehicles will have to explain how the five automakers below managed to do it already, some since 2003.   

  • 2007-09 Toyota Camry
  • 2005.5-09 VW Jetta*
  • 2003-09 Volvo XC90*
  • 2005-09 Toyota Tacoma*
  • 2006-09 Honda Civic*

*Current IIHS Top Safety Pick

By David Thomas | February 5, 2009 | Comments (11)
Tags: Safety



Those models were prbably designed with roof strength in mind (which I think is a good thing)- probably to meet the specifications required previously be another country. It wont be hard to do it for cars that aren't designed that way, but you can't deny that it will cost quite a bit of money.


U.S. Civic and I believe XC90 and Tacoma too were developed specifically for the U.S. market. Regardless, all automakers are moving to global production so it still shouldn't be a cost issue. It's not like the Tacoma has tons of steel in its roof versus an F-150 etc.


Niether the civic nor the XC90 are specific to the US. They are both sold in other countries, where they must meet the safety standards set by those countries.



Manufacturers can complain all they want but in the end they will still comply with the NHTSA regulation (the IIHS is their own standard and is encouraged but strictly voluntary).

And they can complain about the additional weight this regulation will add as it just makes their job of meeting higher fuel efficiency standards that much harder.

F150 roof has to be a lot more robust than Tacoma roof to withstand 4x its vehicle weight because of its higher vehicle weight and its larger size.

And please answer my question about the 2010 Fusion transmissions in that posting when you have a chance.

I was saying that the models were developed specifically for the US market since the US market is where a majority are sold. They are also sold elsewhere. Although there is a different civic entirely sold in Europe.

I was saying the CURRENT F-150 you would think would have more steel in its roof than a Tacoma. Not sure if the F150 was even tested for these yet, I'm just saying the Tacoma's roof isn't so heavy that it hurts its efficiency etc. There are other factors involved to get the strength rating.


The XC90's roof was strengthened during the design stage because of roll overs, even though it has Roll Stability Control System.


Regarding international regulations, I am not aware of any nation with a more stringent roof strength requirement. In fact, I believe there are only 2 nations with any requirement at all, and these simply duplicate the NHTSA standard.


When you make a roof stronger, you add weight above the center of gravity thus causing more rollovers. Then with more rollovers we will need stronger roofs = more rollovers, etc. Tough to design for.


"Manufacturers eager to say these new standards will cost too much or add too much weight to vehicles will have to explain how the five automakers below managed to do it already, some since 2003."

You put five instead of four automakers Dave.


I wonder what roof crush strength force rating my '99 Civic would get? Maybe 5,000 pounds peak force for 5 inches of crush?

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