Skip to comments.Heavier Vehicles Not Always Safer
Posted on 07/30/2002 7:58:36 AM PDT by cogitator
Heavier Vehicles Not Always Safer
ANN ARBOR, Michigan, July 29, 2002 (ENS) - More quality, not more weight, may make vehicles safer, say researchers from the University of Michigan and Lawrence Berkeley National Laboratory (LBNL).
The study counters car industry warnings that tighter emissions and fuel efficiency requirements would force the production of smaller, lighter - and less safe - vehicles.
Physicist Marc Ross and LBML scientist Tom Wenzel have released a report showing that vehicle quality is a better predictor of safety - both for the driver and for other drivers - than vehicle size and weight. Recent Senate hearings on Corporate Average Fuel Economy (CAFE) standards focused on the increased risk Americans would face if they had to give up their sport utility vehicles (SUVs) for vehicles that weigh less.
"We set out to see whether that risk is real, whether SUVs really are safer than cars. The answer, by and large, is no," Ross said.
The first major result Ross and Wenzel found is that SUVs are no safer for their drivers than cars. Popular midsize cars, minivans and import luxury cars have the safest records, while SUVs are about as risky as the average midsize or large car, and are no safer than many compact and subcompact models.
The researchers defined risk as the number of deaths per year per million vehicles.
Other studies have not considered combined risk, which looks at both risk to the driver of the model in question and risk to the drivers of all other vehicles involved in crashes with that model. The study found that, when measuring the combined risk, most cars are safer than SUVs, while pickup trucks are much less safe than all other types of vehicle.
"Clearly the characteristics of the drivers of certain types of vehicles also have a strong effect on their safety," Ross said. "However, it is not clear exactly what that effect is, and the age and sex of drivers do not fully explain these results."
Some of the safest subcompacts also have a high fraction of young male drivers. At the other extreme, elderly drivers dominate certain large cars but there is no clear pattern suggesting that those cars pose higher risk to drivers of other cars as a result.
To determine quality, Ross and Wenzel used quantifiable parameters such as new car price, used car price, Consumer Reports safety ratings, and country of origin.
"It is extremely difficult to determine the inherent safety of a vehicle type or model because it is too hard to separate the contribution of driver characteristics and behavior from the contribution of vehicle design. We can say, however, that quality is a much better predictor of safety than weight," Ross said.
"It turns out that relatively inexpensive light cars do tend to be unsafe, but more expensive light cars are much safer, and are as safe as heavier cars and SUV models," Ross explained. "In any event, the argument that lowering the weight of cars to achieve high fuel economy has resulted in excess deaths is unfounded. If designers pay careful attention to safety in vehicle design, smaller cars can be, and indeed have been, made as safe as larger ones."
Well, no s***. An SUV slamming into a Geo is going to cause a lot of hurt, and not to the SUV driver. But using the "combined risk" method here, the SUV gets docked for safety as much as the Geo. Brilliant.
This is like saying that guns are just as dangerous to the person pointing it as the person he is pointing it toward. This is Green crap.
As my kids would say, "Um, yeah, riiiiight."
What's not safe about this heavy truck?
If you forget to set the parking brake it might roll down your driveway and crush your house ...
Not to be too harsh about it, but I don't buy a Suburban to protect the other guy. I buy it and drive it to protect me and my family. Screw these people and their study.
Not really, I was just commenting on the absurdity of using combined risk as a valid indicator of safety. In addition to the roll factor, SUV and pickup owners are more likely to engage in riskier driving behaviors (off-roading, snow driving, etc.). HOWEVER, common sense (and hundreds of studies) leads me to believe that my personal person is a lot safer in a truck than in a Miata. That said, if you control for seat belt usage, air bag deployment, etc., I bet the safety differences are nominal. No company wants a deathmobile on the market.
OK, I have no beef with trying to use price as a predictor of quality, although I don't think one necessarly follow the other. But how is country of origin supposed to predict quality?? Are the weenies saying that a car made somewhere other than the US is automatically presumed to be better??
And what about using Consumer Reports safety ratings to predict quality?? If they find out these cars actually are safer, it just amounts to saying "Yeah, the cars that those other guys said are, um, safer." If they are trying to correlate to quality, why don't they use the repair ratings as a quality measure? This way, their thesis is "proven" by presuming it to be true in the study design.
Excellent point. That reminds me of an accident I was involved in. I was sitting stopped at a light in the rain in my '77 Plymouth, and was rear-ended by a Honda Civic, who was then rear-ended by a Toyota Genericus. The Toyota had major damage, the Honda was probably totalled, while I had a small scratch on my license plate. ;-)
The bigger the "m" (mass), the smaller the "a" (acceleration). The "a" is what kills.
Certainly, for a given mass, safety is strongly dependent upon design, but that doesn't change the fact that for a given design, heavier is safer.
I'm amazed you're still with us. I was hit from behind by a driver who "didn't see me" and hit full force at about 30mph. She exited her car through the windshield (obviously no seat-belt engaged, along with her brain.) I have permanent damage to my back & neck.
I now have been driving a Suburban for almost ten years. The next fool to rear-end me will be the only one hurt IMO.
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