Are Tiny Cars Unsafe?

There's been a lot of chatter around the blogosphere about the Institute for Highway Safety's report indicating that mini cars fare worse in car crashes than larger vehicles.  This is not exactly news--conservative pundits, and the laws of physics, have been making this point for decades.

This reaction from Michael O'Hare is about typical of the forceful response this drew from proponents of higher fuel standards:

The facts behind the story are that in a collision between a big car and a little one, the little one will be much more damaged and the people inside more hurt. Now you might think this could be thought of in more ways than one, for example that people who choose to drive big cars are putting others at risk, kind of like people who have large vicious dogs, or smoke in bed in apartment houses, or open their car doors without looking back to check for bikes.

. . . Excuse me: why is oversizing and up-weighting not the behavior associated with an increase in deaths on the highway? Why is the "standard" car the fat, thirsty, heavy vehicle of the reckless and self-indulgent? The excess injuries are associated with different sized cars, not small cars; why is the IIHS blithely fomenting an arms race for bigger cars, instead of demanding much higher premiums to insure the road yachts that put sensible people at risk for doing the right thing?

But this is not true, at least according to the IIHS.  The IIHS is, of course, a corporate funded organization--but it's funded by insurance companies that don't like paying accident claims for severe injuries and deaths.  And what the report says is that small cars fare much worse than mid-sized cars, not in collisions with hummers, but in collisions with Honda Accords and Toyota Camry's.  They also do worse in single car accidents.

The death rate per million 1-3-year-old minis in single-vehicle crashes during 2007 was 35 compared with 11 per million for very large cars. Even in midsize cars, the death rate in single-vehicle crashes was 17 percent lower than in minicars. The lower death rate is because many objects that vehicles hit aren't solid, and vehicles that are big and heavy have a better chance of moving or deforming the objects they strike. This dissipates some of the energy of the impact.

Some proponents of mini and small cars claim they're as safe as bigger, heavier cars. But the claims don't hold up. For example, there's a claim that the addition of safety features to the smallest cars in recent years reduces injury risk, and this is true as far as it goes. Airbags, advanced belts, electronic stability control, and other features are helping. They've been added to cars of all sizes, though, so the smallest cars still don't match the bigger cars in terms of occupant protection.

Would hazards be reduced if all passenger vehicles were as small as the smallest ones? This would help in vehicle-to-vehicle crashes, but occupants of smaller cars are at increased risk in all kinds of crashes, not just ones with heavier vehicles. Almost half of all crash deaths in minicars occur in single-vehicle crashes, and these deaths wouldn't be reduced if all cars became smaller and lighter. In fact, the result would be to afford less occupant protection fleetwide in single-vehicle crashes.

Yet another claim is that minicars are easier to maneuver, so their drivers can avoid crashes in the first place. Insurance claims experience says otherwise. The frequency of claims filed for crash damage is higher for mini 4-door cars than for midsize ones.

The outrage at the Times is not reality based.  Small cars simply are not as safe as bigger cars, and they can't be made safer by yelling at people who insist on believing in the laws of physics.

I say this as the proud owner of a used Mini Cooper S.  I was aware when I bought it that it was not as safe as owning an SUV.  Like the hippie environmental whacko moralist I am, I believe that I have an obligation to drive the smallest car possible, when I drive, even at some extra risk to myself.  I also like the gas mileage, the extreme ease of parking, the turn radius, and, yes, the styling.  Life is full of tradeoffs.

On the other hand, I live in a city, and do most of my driving at speeds well below lethal.  My bullmastiff does not require a carseat.  And my recently formed household includes (rare for DC) a second car, a midsized sedan that can be used for highway driving.  It's not as if I've really leaned into the strike zone to take one for the team. 

As long as Americans insist on having children, and those children are legally required to spend their prepubescent years in some elaborate safety contraption, American cars aren't going to get much smaller than an Accord.  And those Accords will continue to pose a mortal threat to those of us who drive smaller cars.

This is a real problem for proponents of higher fuel economy, not to mention the manufacturers of small cars.  Cheap, fuel efficient cars are more dangerous.  Even hybrids rely at least in part on making the car lighter.  On the other hand, running a massive uncontrolled experiment on the global climate seems kind of dangerous too.