'Offset' crash tests find higher risk for smaller cars

There’s an old saying -- you can’t repeal the laws of physics. That may be the discussion right now at several small-car manufacturers today.

The Insurance Institute for Highway Safety, known for its slow-motion car crash videos, sent the Honda Fit crashing into a Honda Accord, the Smart ForTwo into a Mercedes C-Class and a Toyota Yaris into a Toyota Camry -- each at 40 miles per hour. The results indicate what safety you may be trading for efficiency when your mode of transportation shrinks.

The tests are called "offset" crashes. The cars crash not quite head on, similar to what would result when a car strays over the center line, and the damage can easily intrude into the passenger compartment. Each of the small cars sustained damage the institute believes would lead to injuries for their occupants.

In a statement, Adrian Lund, president of the Arlington, Va.-based institute, said, "Though much safer than they were a few years ago, minicars as a group do a comparatively poor job of protecting people in crashes, simply because they're smaller and lighter. In collisions with bigger vehicles, the forces acting on the smaller ones are higher, and there's less distance from the front of a small car to the occupant compartment to 'ride down' the impact. These and other factors increase injury likelihood."

The Smart ForTwo had “extensive” damage...

...into the area where the driver sits. The institute's findings indicate a human would have a high likelihood of sustaining head and leg injuries. The Yaris rated poor in the area of head and leg injuries as well. A driver of the Fit in a similar accident would have hit the steering wheel through the airbag in addition to sustaining leg injuries.

What say the manufacturers? In a statement, Dave Schembri, president of Smart's U.S. operations, called the test an example of a “rare and extreme” accident. “The Smart ForTwo meets or exceeds all U.S. government crash-test standards," he said. 

Toyota’s statement said the institute's test was equal to an 80-mph collision, which was “a speed and energy higher than 99.1% of all real world crashes."

Honda’s statement also said the tests were done at a higher speed than most real world crashes and that, for the company, “Safety is a top priority.”

Institute for Highway Safety spokesman Russ Rader said that the test was not done any differently than past front crash tests, but that the automakers use the combined speeds of 40 mph on each car to come up with the 80-mph complaint. 

"This new test is no different than others they have done in the past -- both vehicles are traveling at 40 miles per hour so the closing speed could be considered 80 miles per hour," Rader said. He added that the test configuration is exactly the same as crash test results the automakers use in their safety advertising.

UPDATE - Corrected typos in quote from IIHS statement 

-- Doug Stewart

Photo: Smart ForTwo crash test by the Insurance Institute for Highway Safety

Comments

[K.Leffler]

The statement you quoted from the institutes chairman, Mr.Lund is unfortunately quite incorrect. It read
"In collisions with bigger vehicles, the forces acting on the smaller ones are higher."
That would be completely impossible.

I went to the website of IIHS, however, and their actual study makes no such errors. There they state that the forces on the OCCUPANTS of the smaller car might be larger in the microseconds after the initial collision. This might be true.

[Remco deJong]

During the reign of Bush 1, the National Highway Traffic Safety Administration, NHTSA, made videos of a 1950's era Cadillac crashing head first into a Honda Civic. When the Honda was crushed by the Cadillac the conclusion was that, "Big cars are safer than small ones." And: that to be safe, you should get a big car. They aired these videos all over television. There was speculation that these videos were pandering to Detroit and pushed for their SUVs. The other answer is that: Everyone should get small cars and then there is no comparative benefit. Now clearly everyone won't Fit in the small Honda so there is bound to be some disparity of vehicle size. Gratefully they didn't smash a Ford Mastodon into the Smart for Two or the fear factor of driving one of these small cars would inhibit all but the most brave or fool hearty from driving these frugal, fuel sipping, relatively green machines. I believe that the fear of driving a small car generated by this type of study generates an equivalent to an arms race on the road that is more detrimental to our collective future (higher gas prices, more CO2, etc) than the additional danger of driving in the small cars.

But I don't think I'll get one for my wife.

http://www.iihs.org/video.aspx/releases/pr041409

[Andres Espina]

I think this report is just a part of the true. This report should also comment about the crashes between all vehicles sizes: mid cars, big cars, trucks and eighteen wheelers. Then, compare the effects of the size and mass over the survival statistics. Several conclusions can be done depending on every drivers point of the view and the Physics Laws. a) The big cars are dangerous for smaller cars. b) Bigger cars provides more protection against smaller cars. c) Crash between same size cars are equally destructive for both cars.

Additionally, they should also public a cake graphic with the percentage of car sizes on the streets to give and idea of what would be the most likely car to crash with. This would give a better perspective for potential car buyers to decide between a race for a safer and biger car or a smaller and economic one.

[Robert G]

It didn't take a collision to convince me that these things are death traps. In my area, there is a poorly designed patch of interstate where dozens of cars enter and exit at high speed. Multi-car collisions, spinouts, etc, occur once every 2-3 months. At least one of these cars is left undriveable, but the occupants mostly seem to emerge with minimal physical injury. This is because the cars' bodies crumple AROUND the occupants, not into them. These "smart-cars" don't seem have enough material to absorb impacts the way their larger cousins do.

I understand the need for fuel efficient cars, but perhaps we need larger, but lighter cars made of composites that can be made to collapse safely around occupants.

[Bored]

Does this mean we should all drive trucks? These findings could be interpreted in many ways. We need to do more studies. What about small cars hitting small cars compared to big cars hitting big cars? Perhaps, aggregate road safety will increase if most of our cars are small.

These cars are almost necessary considering gas prices and the environment. So it would make sense if we invest money on how to make the roads safer with these vehicles, not looking for ways to keep them off the road.

[Louis-Jacques Sereville]

LOL, most classic! Give the 2009 Ig-Nobel Prize to the Insurance Institute for Highway Safety.

Indeed, the bigger are generally safer than the smaller are, but everybody already knows that they are generally safe enough after all.

Raise the insurance premiums for small cars to protect America, lol.

[roman]

I wouldn't want to be in a offset 40mph crash between two SUV's either.

[ferenc]

did they needs to spend millions on a test to prove this? i could have told them for free!

[Budget Rental Cars]

The test results have nothing to do with manufacturers statements or opinion.I think the narrow bonnet is the main reason for injury to front seater.This kind of test are must, this makes the small car holder aware of the precaution to be taken.

[bp]

while a crash at any speed is a problem, there is a huge difference between two cars crashing, each going 40 mph, and one car going 80 mph. the formula for the energy at impact equals mass times velocity squared. the energy of the test was 2 times mass times 40 mph squared. the energy of the impact the Rader describes equals mass times 80 mph squared. Huge difference. Rader need to speak with his engineers a bit more if he is confused.

[Cristina Gray]

Duh!!!

[Ed]

This is a sensationalist article, the test is equivalent to the standard deformable barrier test being carried out at 80mph. It would be interesting to see the results for both sets of cars from that as a comparison.
Other reference tests as a previous comment said should be each car vs a car from the next size class up.

Look on youtube for footage of a Smart car being crashed into a solid concrete barrier at 60-70 mph from the car show Fifth Gear, you'll be surprised at how well it survives.

I can't help feeling this is a ploy on the part of the insurance industry to justify higher premiums.

[jose morais]

In fact, two equal cars slamming at each other at 40 mph is the same thing as a single car slamming at 40 mph against a rigid wall: by symmetry, the contact plane will not budge one way or another (the cars are equal) so it’s the same thing as hitting a wall (speeds don’t add up, so 40+40 is not equal to 80 in this case).
However, when two different mass cars crash at 40 mph, symmetry does not apply, and the contact point moves in the direction of the lighter car. So, comparing with the crash against a rigid wall, the heavier car will see the contact point at a lower speed, and the lighter car at a higher speed, the difference depending on the relative masses (momentum conservation).
If the heavier car has double the mass of the lighter one, the contact point will move at 13,3 mph against the smaller car. So for it, it will be the equivalent of a 53,3 mph crash against a wall, while for the heavier car it will be a crash equivalent to 40-13,3=26,7 mph, only half the speed.
These are the ineluctable laws of physics…

[Alex Law]

The story left out the most important stat -- the death rates in real world crashes, which show that Civic-sized cars have a fatality rate three times higher than full-size cars or minivans. On top of that, if the Civic driver survives, she will likely have more injuries.
The most common vehicle size on the road is a pickup truck, which can weigh three times what a Civic weighs.
This is not news for anyone who has studied the literature (IIHS, NHTSA, Euro NCAP, etc) on a regular basis, but it does seem to have come as a shock to most of the professional auto writers in the US. But they don't pay attention unless they're going to Europe to drive a new car or wondering what time the company will deliver their next tester. Those folks have been telling you that cars with five-star crash ratings are safe, and they have been misleading you.

[Lynn]

I think the whole point of this report is other than the obvious "small car = more injuries".
Today's small cars are much safer than their 10-20 year old counterparts.

[Bobby G. Beaman]

Looks like we need to stop driving all cars and take a bus or train. Note, I would be dropping my insurance also at that point.

Mass Ratios? Honda 1.395, Toyota 1.582 and Mercedes 2.110. I think anything that gets hit with these mass ratios will have similar damage. The Mercedes Smart car went air born (was missing the side air bags also). Bouncing off the collision changes the game. Even though mass ratio was highest and no side air bags the Mercedes Smart car is a game changer. The Smart features are safest car ever. Mercedes Smart car is a game changer.

[Steven Baer]

One other aspect to consider in safety testing like this is the idea of passive versus active accident avoidance. While smaller cars tend to sustain more damage in collisions with larger ones (as we all intuitively understand), small cars tend to be better at avoiding accidents in the first place; this is active control. It would be interesting to see the statistics on crashes and fatalities by vehicle type.