IIHS Conducts First Tests for Roof-Strength Standard

Roof-strength The Insurance Institute for Highway Safety has launched its new roof-strength rating system, conducting its first batch of tests on small SUVs. Only four of 12 vehicles managed to earn the top rating of Good.

The SUVs rated Good were the Subaru Forester, Honda Element, Jeep Patriot and Volkswagen Tiguan. The Suzuki Grand Vitara, Chevrolet Equinox, Toyota RAV4, Nissan Rogue and Mitsubishi Outlander were rated Acceptable. The Honda CR-V and Ford Escape ranked Marginal, while the Kia Sportage and Hyundai Tucson were the only small SUVs to rate Poor.

The new roof-strength standard is meant to combat rollover deaths, which at more than 10,000 a year account for roughly a quarter of all traffic deaths. To become an IIHS Top Safety Pick, vehicles will now have to withstand four times their own weight before the roof collapses 5 inches. This strength-to-weight ratio is much higher than the National Highway Traffic Safety Administration’s standard, which mandates that roofs bear 2.5 times the vehicle’s weight.

The four-times figure wasn’t plucked out of thin air: IIHS says this level of strength could lead to a 50% reduction in fatalities during rollovers. IIHS says including this qualification in its list of Top Safety Pick standards should significantly lower the number of cars — 73 today — that earn that status.

Currently, the Ford Escape, Honda CR-V, Honda Element, Mazda Tribute, Mercury Mariner, Mitsubishi Outlander, Nissan Rogue, Subaru Forester, Toyota RAV4 and VW Tiguan are rated as Top Safety Picks. This test would cull this list of 10 to only the Honda Element, Subaru Forester and VW Tiguan.

Though there’s been much debate between the government and automakers about the cost and necessity of roof-strength standards, this move by IIHS won’t leave companies much choice but to add to roof strength while trying to keep overall vehicle weight down, lest they be outpaced year after year in IIHS testing.

The Institute will next test roof strength of minicars and midsize cars.

By Stephen Markley | March 23, 2009 | Comments (33)
Tags: Safety



The IIHS should be applauded for its efforts. They have done more in the past 8 years to improve high speed front/side/rear impact and now rollover safety in real world conditions than the NHTSA did in decades. I've been waiting for more realistic roof strength tests, and the IIHS will once again separate the men from the boys and force automakers to show that safety doesn't have to come at the expense of fuel economy.


Reminds me of the Volvo commercial back 20 years ago that showed GM roofs buckling while the Volvos could hold the weight of another vehicle. Just one problem, the ad agency had hacksawed the GM roof supports. Volvo had to admit they twisted the truth.

Derrick G

Oops. It's not the Soul that was the Kia that was tested. It was the soon-to-be replaced Sportage.


How did the Tata Nano do in this test?

Hewhocannot Benamed

Ford Statement in Response to IIHS Report on Roof Crush

DEARBORN -- The Escape has a proven real-world safety record and earned an IIHS "Top Safety Pick" award with top ratings in front, side and rear tests. Insurance industry injury claims data shows Escape performs well in all types of accidents, including rollovers, when compared to all types of vehicles.

....The Ford Escape is the only small SUV to offer a stability control technology – AdvanceTrac with RSC (Roll Stability Control), which is standard equipment – with a roll-rate sensor that helps the system detect and prevent rollovers. Escape also offers as standard equipment Ford’s unique Safety Canopy system with rollover-activated air curtains designed to help reduce rollover injuries and the risk of ejection.

Decades of science-based testing and data analyses clearly demonstrate that safety belts are the single most effective device in reducing the risk of injury in a rollover, regardless of roof strength, and roof strength increases alone will not provide measurable real-world safety benefit in rollovers.

Thanks. Had Soul on the brain I guess.

Hewhocannot Benamed,
I'll leave the response up but the IIHS has a pretty good record with these types of tests and even if half of how many lives can be helped with increased roof strength I think it would be hard to argue against it. Especially using the Seat Belts line. Isn't seat belt use at an all time high? Like 70+%?

And if Subaru can do it in an SUV that's less money than the Escape how come Ford can't? That's what consumers will be asking.


"...testing and data analyses clearly demonstrate that safety belts are the single most effective device in reducing the risk of injury in a rollover..."

Not sure how safety belt can save you from the collapsed roof hitting your head.


And also, did they tell that half drivers were dead in their cars before the rollover?


The question to ask is what percentage of people who died in rollovers were not wearing their seatbelt.

Ford is right in that a static roof test is not a good predictor of overall rollover crash protection. The IIHS should have gone a step further to a dynamic rollover test simulating what happens in a true rollover where all systems can be evaluated: roof strength, safety belts, side window integrity, side curtain airbags and door latch integrity.


Ford's response is no surprise- they are obligated to make such a response to put their product in the best light while it is re-engineered to improve roof strength.

My name is Wes Sherwood and I am the safety communications manager at Ford. We appreciate the opportunity to respond to your comments. Here is more information compiled from decades of rollover research that may be helpful:

* More than 95 percent of belted occupants in rollovers are not seriously injured.

* Safety belts are approximately 75 percent effective in reducing fatalities in rollovers.

* The government found that 53 percent of those fatally injured in rollovers were ejected from the vehicle and 72 percent of those were unbelted.

* The government stated in their rollover ruling, "Regardless of the amount of roof deformation in rollover crashes analyzed by NHTSA, more than 98 percent of belted occupants did not receive serious or fatal head/neck/face injury from roof contact." http://www.nhtsa.dot.gov/cars/rules/rulings/RoofCrushNotice/216NPRM-to-FR.html

Well if 53% are ejected in rollovers and IIHS says this will help 50% of fatalities are they far off?

With so many deaths in these types of accidents wouldn't let's say 25% reduction be a huge impact? 2,500 lives? That's a lot. Especially considering so many traffic deaths are being prevented in other types of crashes yet rollovers remain relatively high.

I think there are plenty of stats to go around. The Forester kind of proves you can do this without a huge cost and with plenty of visibility too.


Wes- thanks for contributing to this discussion. Reading through the NHTSA report, I also found these stats / statements:

"Although the injury risk estimates for belted occupants are lower, they remain higher for rollover crashes than for other crash modes."

-- I think it's important to look at not just fatalities, but "fatally OR seriously injured" stats:

Risk of Fatality and Serious Injury to Occupants
of Non-Convertible Light Vehicles Involved in a Towaway Crashes by Crash Type
Rollover 7.2%
Frontal Impact 2.1%
Side Impact 2.5%
Rear Impact 0.6%

"The agency previously estimated that approximately 64 percent of about 10,000 occupants fatally injured in rollovers each year are injured when they are either partially or completely ejected during the rollover. Approximately 53 percent of the fatally injured are completely ejected, and 72 percent are unbelted. [22]"

-- Does this not imply that 28% of those fatally injured are wearing seat belts?

-- Do you not agree with extending the roof strength requirement from cars to light trucks / SUVs with GVWR > 6,000lbs?

Some more interesting points from the NHTSA article:

"Under the first alternative, we estimate that this proposal would prevent 793 non-fatal injuries and 13 fatalities. Under the second alternative, we estimate that this proposal would prevent 498 non-fatal injuries and 44 fatalities. The annual equivalent lives saved are estimated at 39 and 55, respectively."

-- Do you disagree with this NHTSA assessment? If so, what does your data show?

"The estimated average cost in 2003 dollars, per vehicle, of meeting the proposed requirements would be $10.67 per affected vehicle. Added weight from design changes is estimated to increase lifetime fuel costs by $5.33 to $6.69 per vehicle."

-- Do you disagree with this cost estimate and fuel cost increase? If so, what does your data show?

Like Dave said, the Forester, Element, Patriot, and Tiguan prove roof strength (one component of safety in rollovers, in addition to toll stability control and roof airbags + seatbelts) can be increased while not significantly affecting cost, visibility, or fuel economy.

The NHTSA data shows lives can be saved. IIHS data also shows their testing standard could reduce rollover fatalities by 50%. What does your data show, and why is your response not "one aspect of rollover safety is roof strength, as shown by NHTSA and IIHS data. (in addition to rollover stability control, airbags, and seatbelts). We can improve the roof strength of our vehicles without significantly affecting cost, fuel economy, or visibility- as proven by our competitors. We may even be able to apply technology from the XC90 to our Ford lineup. We agree with making GVWR > 6k vehicles meet the same roof strength safety standards as GVWR < 6k because we want to go the extra mile to make our car and light truck passenger safe. As shown by the NHTSA and our competitors, we can do this at negligible cost, fuel economy tradeoff, and visibility tradeoff." Can you explain to me why this is not your response of the safety of your customers is not of prime importance?


Thank you for responding. Our research (and that of others) has shown the rotational and gravitational forces acting on belted and unbelted occupants in rollovers can result in the occupant's head being close to or in contact with the roof before the roof contacts the ground or other objects, and before roof deformation occurs. Rollover crash tests have shown that this impact will impart forces on the occupant’s head before significant roof deformation begins. So, the crushed roof contacting the head does not cause the potential head or neck injury, rather it is the impact between the roof, with the head in contact with it, and ground or other object.

In frontal or side impacts, increased deformation typically is associated with increased injury or risk. However, the vehicle deformation is not necessarily the cause of the injury. Rollover crashes are no different than frontal or side impacts in this respect. As with all other types of vehicular crashes, vehicle deformation and injury severity are indicative of impact severity. That doesn not mean that in a rollover crash, roof deformation is necessarily the cause of occupant injury in that crash.


Wes- I'd appreciate a response to my post, as well, if you have time.

Your last post seems to contradict the IIHS' claim that their roof strength recommendation would reduce rollover fatalities by 50%. What do your numbers show in terms of the reduction in fatalities if the IIHS roof strength recommendations are met? 0% reduction? 15% reduction?

You seem to be setting up a straw man argument by saying that increasing roof strength alone isn't the answer. Roof strength is not the only component in occupant safety in rollovers and I don't think anyone is arguing this. Rollover stability control, roof airbags, and seatbelts that keep occupants in their seats are all important, but I think you are minimizing the fact that roof deformation is ONE FACTOR in occupant safety. The IIHS and NHTSA both show reduced fatality rates with increased roof strength standards. Do you dispute that roof strength is one factor in occupant safety and do you dispute the NHTSA and IIHS data that shows this?

Ken L.

Has it ever occurred to anyone that a stronger roof could mean a heavier roof? A heavier roof on a SUV with a higher center of gravity means an INCREASE for a potential rollover when performing an emergency maneuver. Just a thought.

Derrick G

Perhaps everyone should read the IIHS's "Status Report" on the issue:


The Institute has crushed older models of both small cars and SUV's and compared the results with real-world crashes and found a strong correlation between strong roofs and fewer injuries and fatalities. The Institute also disputes the large number of rollover fatalities that NHTSA just automatically excluded from its projections.

As far as causing more rollovers, vehicles with stronger roofs actually were slightly less likely to rollover.

And though the IIHS would like to see a dynamic test, there's no dummy for it yet anyway.

Lastly, it's worth pointing out that the Subaru Forester is a fairly light vehicle for the class, has narrow pillars that don't obstruct view, and yet still gets a Good.



1. Has it ever occurred to you that the Subaru Forester, Honda Element, Jeep Patriot and Volkswagen Tiguan all have the best IIHS roof strength ratings and they all have comparable rollover risk scores from the NHTSA vs. the vehicles that scored below them in the IIHS roof strength test?

2. Has it ever occured to you that Ford/Volvo is already implementing a much stronger roof in the Volvo XC90 and this is not by use of more of the same material (making it heavier / more tipsy), but rather by using different materials (boron steel, aluminum, magnesium)?

3. See Derrick's post (above) about the IIHS data showing rollover behavior counter to what you're implying.

I think you're oversimplifying things here...a lot.


If the people can drive with reasonable speed, they shouldn't roll over.


C- yes, because accidents where other vehicles run into yours and cause your vehicle to rollover do not exist, nor drunk drivers who make unexpected turns requiring you to make emergency maneuvers at high speed, nor poor road conditions / weather combined with the above. I'd love to live in your fairy-tale land.


On a related note, from the Detroit News no less, an article about Ford's Explorer vs. the Ford subsidiary Volvo's XC90:

"Memos: Ford made Explorer roof weaker"

Please note that I'm not a Ford basher here. In fact, I have a lot of respect for Wes for coming on here to respond to comments- note that other automakers aren't doing the same. My family has owned 4 Fords, all good experiences. I also think Ford is paving the way forward for American automakers in this tough economic time with excellent quality, fuel efficient, safe vehicles. I just don't agree with Wes' vague defense of their products without directly contradicting or even talking about the IIHS and NHTSA recommendations and fatality reduction numbers. Ford isn't the only automaker conforming to the minimum when it comes to light trucks and roof strength.

Derrick G


Think you hit the nail on the head. Ford seems to be doing a lot of things right, but reading things like the comments Wes has made gives me pause. Had he said we're on it and in the meantime, buckle up, that'd be one thing. But the same old pattern of vaguely disputing the validity of the tests and standards just makes me uneasy.

Same can be said of the comments Jim Trainor of Hyundai made about Cars.com's removing the Sonata's Best Bet designation.

As a consumer, I'm tired of hearing such, especially when other companies are meeting the criteria before the IIHS even formally introduced it and when both companies readily advertise the Top Pick ratings on their cars that achieve it. Both have even made running changes to cars just to get that rating.

Thank you for your comments, and sorry for the delayed response. In terms of the government's efforts, the Alliance for Automobile Manufacturers – which includes Ford, other domestic companies and foreign automakers –stated late last year that we “support NHTSA’s goal of enhancing rollover safety through a comprehensive plan aimed at eliminating rollover injuries and fatalities, and enhanced roof strength is only one part of that plan. The best way to save lives and prevent serious injuries is to avoid situations that lead to rollovers, in part, through the industry’s groundbreaking initiatives including Electronic Stability Control, Lane Departure Warning systems and other driver assist technologies. Safety belt use is the most effective device for reducing the risk of serious injury or fatality."

Also, this new report is a statistical analysis but doesn't include an engineering analyses of what happens to occupants in rollovers - something that we believe is very important to fully analyze important topics such as this. Ford and others have studied this dynamic to help shape our opinions.

Finally, I think some of the characterizations of Ford's safety efforts are unfair given than we have the most IIHS "Top Safety Picks" of any company, offer the industry's only stability control system that helps detect and prevent skidding AND rollovers, and are pioneering new technologies such as SYNC and MyKey that help address major issues such as driver distraction and teen safety. We also introduced the first side air curtain system – Safety Canopy – with extended deployments to help provide protection in rollovers.

Ford's Roll Stability Control and Safety Canopy system are now standard on most of our crossovers, pickups and SUVs. We also are not standing still on enhancing our vehicle structures to build on our leading crash-test ratings. As this report notes, vehicle roof strength is increasing as a byproduct of automakers' efforts to help enhance safety in the most common frontal and side impacts. We think you will see that Ford vehicles are following this trend as other vehicles are tested.

Just to be clear on our position, we believe roof strength should be considered within a holistic look at rollover safety. But, this report could create the mis-conception that roof strength alone will help, which has been shown not to be the case.



If you've been paying attention to the road, you could easily predict who is not paying attention and stay away from them. Emergency manuver? Don't tailgate the others. Poor road conditions? Slow down.

Blaming the others for our own actions is not gonna end.


C- I cannot believe I am responding to your post, but here goes:

I see you ignored my example of other cars striking your vehicle- what about that case? Are you saying you can always avoid other vehicloes coming at you? What if the other vehicle is spinning out of control and coming at you out of the blue sideways as a result of another accident? What about the drunk driver who suddenly merges in and swerves into your lane and you have nowhere to turn? You can be a perfect driver, even a professionally trained driver, and still get into a lot of situations beyond your control that could cause rollovers.

By your incredibly flawed logic, all accidents can simply be avoided by cautious driving, so why waste money on seatbelts, airbags, crumple zones, or side impact door beams?

Blaming improper driving for situations out of the driver's control (or at least pretending these situations do not exist and are not common) is ridiculous.


C- I almost forgot some rollover scenarios I've seen in person: a driver decides to run a red light and T-bones an SUV, causing a rollover. Or a driver suddenly decides to gun a left turn at the very last minute before an oncoming vehicle approaches, giving the oncoming vehicle no time to react. The resulting collision caused a rollover. Again, by your logic, I could argue against every major safety advancement back to the safety belt since all it takes it some cautious driving to avoid accidents.


Wes- I appreciate you coming onto these forums to talk about rollover safety and roof strength. I think it says a lot for Ford, and I don't deny Ford has done a lot in rollover safety with rollover stability control, canopy airbags, and a first-in-class high strength roof in Ford subsidiary Volvo's XC90.

The same research that Ford subsidiary Volvo has done showing reduced risk of fatalities in Volvo's XC90 IN PART due to increased roof strength (along with more effective seatbelts, rollover stability control, and canopy airbags) and that this was done without excessive cost, fuel econonmy, or visibility compromises, cannot be denied. Looking at the video comparison of the Ford Explorer vs. the Volvo XC90, one also cannot deny the obvious increased safety provided by the XC90's roof structure as ONE PART of the safety equation. The fact that Ford's own subsidiary Volvo's data supports stronger roofs as part of occupant safety in rollovers makes it almost impossible for Ford to deny it or even be vague about it in any way. Instead, I would hope that Ford would borrow some of this technology for their own vehicles in addition the technology they already use.


What do you mean, "...add to roof strength while trying to keep overall vehicle weight down..." ?

Remember, 2 of the 3 vehicles rated GOOD are not notably heavier than the lesser vehicles, they're just better designed. (the VW is a heavyweight.)

Ronnie J

C says: "If the people can drive with reasonable speed, they shouldn't roll over."

Tell that to the families of the dead people who's unstable Ford Explorer unexpectedly and suddenly rolled over, and the Explorer's weak roof easily collapsed and crushed their heads and killed them. Just Google images for "SUV Rollover" or "Explorer Rollover" and you will see inadequate roof strength is not a small problem.

Maybe if people just don't ever leave their house, they'll reduce their risk of injury in a rollover accident. Gees.

I learned something here. Thanks for posting.

I have the same opinion as yours on this. What you said is true.


This discussion is "All very interesting", mostly as an example of how folks who are actually "on the same page" seem to be in conflict. I am impressed with Wes' input, but believe the fine distinctions he is attempting to communicate (essentially that roof strength is only one factor amongst many variables within the total rollover-to-injury envelope) has only served to cloud the discussion. This, I am sure, was not his intent.

I believe anyone here can agree that, all other factors being unchanged, a stronger roof will reduce rollover injuries *in total*. However, in the "real world", each incident is certainly unique and is composed of many factors that impact the outcome. The real challenge (for engineers) is to come up with a realistic, testable "safety system" model that can incorporate all significant factors and will give accurate results every time. With such a tool, it is possible to apply the "best for the most" principle without making a vehicle that "most" cannot afford.

After all, I suspect no car will ever "win" against a speeding train (for example.)


Pauline Y

I am surprised at how poorly the Honda CR-V and Ford Escape performed, especially considering how each company touts it's safety. Go figure.

Ronnie (above) is right on track.

After several days of research, it sure appears to me that Ford, in particular, has a long history of bean-counting how little their customers lives are worth, from the Pinto, Mustang II, Bronco II (Explorer), etc...

But Ford forgets that 'Dead customers can never become repeat customers'.

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