Americans, according to recent opinion polls, believe that global warming exists and would support measures to curb it, even if it means being hit in the pocketbook. One measure they could take -- and save money doing it -- would be to think twice before buying one of those sport utility vehicles that have sprung up across suburbs and cities like mushrooms. Only some 13 percent of SUVs are ever driven off-road. They're expensive, guzzle huge amounts of gas and emit a lot of pollution because many of them are classified as "light trucks," which are subject to easier emission standards.

They are also killing people in what are called "mismatch" car crashes. Some auto insurers are planning rate raises for SUVs because research suggests they inflict worse damage to smaller vehicles and their occupants in such crashes.

Salon talked with Kim Hazelbaker, senior vice president of the Highway Loss Data Institute. The insurance industry-funded institute, along with its sister organization, the Insurance Institute for Highway Safety, are conducting studies on "mismatch" car crashes this fall and winter.

What are "mismatch" crashes?

There are a couple of issues when you have large SUVs getting into crashes with smaller passenger cars. One is the obvious size mismatch. The average SUV is heavier than the average passenger car and physics being what it is, that's a bad thing for the passenger car in a multi-car collision.

The second mismatch is the bumper height. Most SUVs are four-wheel drive, which were designed originally for off-road use. They sit up higher than passenger cars, and many times when they get into crashes with passenger cars the bumpers do not meet. So you have a collision in which the SUV suffers little or no damage to its bumper, but that bumper's done a lot of damage to the metal panels of the vehicle that it hit.

Is this mismatch reflected in the injuries involved?

So far we've only done a limited investigation, into property damage losses. We don't at this point have hard data on the injury side, although one would unfortunately have to come to the conclusion that the likelihood of injuries is greater.

But there has been some comparative crash testing done in Europe.

Yes, and they show what you would expect -- that more physical damage is done to the smaller car and that dummies inside that car are more likely to sustain injuries. A German study crash-tested a Nissan SUV and a Volkswagen Golf nearly head-on. The crash test dummy in the Golf got head injuries measured at nearly 3,200, on a scale where 1,000 is fatal. A British study indicated that SUVs and pickups are especially dangerous when they hit an ordinary car side on.

Isn't it true that in the U.S., while mismatch crashes still are a minority of two-vehicle crashes, they now account for the majority of deaths in two-vehicle crashes?

Yes.

Many people buy SUVs because they look safer. But really it's safety at someone else's expense.

The data are pretty clear that SUVs do a good job of protecting their own from death and injury, and a pretty good job of not suffering much vehicle damage in collisions. The downside is, the other vehicle in the crash is not going to fare as well. The message on the safety side is: It's good for the occupants of the SUV but not good for the occupants of the other vehicle.

Apart from the height and weight mismatch, do people also tend to drive SUVs less carefully because they're driving such big vehicles?

The marketing data the car companies share with us shows that one of the aspects people really like about SUVs is the feeling of invulnerability. You sit up high -- that's always mentioned. You can see over other traffic. On the other hand, the message the driver gets is that he's going to be able to push everyone else out of the way. That's not a good thing.

Isn't there also the danger of rollovers with some SUVs?

Yes. The small SUVs are particularly troublesome. They're very popular with kids. Unfortunately, we as a society have a tendency to put our least experienced drivers in some of our more dangerous vehicles.

Is the increasing popularity of SUV's leading to more deaths and injuries overall? Well, for many years we've seen a decline in the overall deaths caused by auto collisions. In the last couple of years, that decline has stopped. There's a number of reasons for that, including raising the speed limit in many states. But clearly the change of vehicle size in the nation's fleet also has an effect. SUVs seem to be getting bigger and bigger. Aren't there regulations limiting their size and weight? No, there really aren't. For example, Ford has one of the hottest products on the market right now, the Ford Expedition, which I understand you have to pay a premium to buy. They're planning to build a vehicle which would be so large it would not be categorized as a light-duty passenger vehicle, and would fall outside of the Corporate Average Fuel Economy -- the so-called CAFE law -- which regulates what the overall fleet of a manufacturer has to get in terms of gas mileage. This new one would weight more than 8,500 pounds; it would be a medium-sized truck! I guess I don't quite understand the market for that sort of vehicle. How much bigger is this 8,500-pound monster than the SUVs currently on the road? The biggest SUVs out there now are the Chevy Suburban and the Ford Expedition, both of which are in the 5,000-6,000 pound range. What does a mid-sized car weigh? 3,500 pounds or so. It makes one wonder if the next SUV will be a tank. Exactly, and that's sort of out there in the Hummer. What regulations are there on bumper height? There's a range within which the bumpers must fall in. Unfortunately, if you have a passenger car, which is toward the bottom of that range, and you have an SUV toward the top of that range, they don't meet. So what happens when they collide? You get stiff bumper material pushing rather dramatically into car panels. About where a driver's or passenger's head and chest are. Certainly in the case of a side impact, it's potentially lethal. What specifically are you looking for in your studies? We're updating a previous statistical study that documented the higher losses associated with the liability coverage for SUVs. The second thing we'll be doing is a fairly detailed analysis of fatality data, to look at what happens in SUV and passenger car crashes. The third thing is we'll be doing some crash testing between sport utility vehicles and passenger cars. Can you give us an idea what you've learned so far? Early indications in the statistical study are that it will show pretty much the same kind of pattern that we saw before: higher losses being caused by the SUVs. That's important because there are many insurers looking at repricing portions of their insurance for SUVs. Two have already upped their rates. Yes, Farmers and Progressive. And based on the phone calls I've been getting, there are a number of other insurers that are certainly interested in looking at the data. I'm also getting calls from drivers of small cars who say, "You're telling me I'm getting run over by these bigger vehicles and I'm also subsidizing their insurance?" And the answer's yes. How high might the SUV rates go? Liability rates for drivers of SUV's could be hiked by as much as 20 percent over the next few years, while car owners would get a cut of 10 percent. Do you think insurance increases will affect the SUV market? I have to say, you're looking at people who are willing to put out -- what? -- $40,000 up front for one of these things, plus high operating costs and less gas mileage. Is getting the liability portion of their insurance increased a disincentive? I don't believe it would affect very many people. So what would you want to see? If something could be done about the height mismatch, I think both property loss damages and potential injury could be lessened. We've had some interest from manufacturers, including Ford, in seeing what could be done about this. What do you drive? A Lexus. Why? It's done well in our crash tests. And in the real world of injuries and fatalities, it's done very well. In terms of my safety and the safety of my family, I'm happy with it.