On The Safety Of Large Vehicles

Edward Niedermeyer
by Edward Niedermeyer
on the safety of large vehicles

The “big car safe, small car unsafe” debate took another interesting turn this week, as researchers from UC Berkeley have released a report arguing that large cars significantly increase the risk of death on American roads. Recent data on the most and least died-in vehicles seemed to show that larger vehicles do indeed keep drivers safer, but this new report seems to roll back the impact of that finding. Slate reports that researchers

studied accident data from eight states, identifying the type and weight of vehicles involved in collisions by their VIN numbers. The researchers confirm that the heavy cars kill. Indeed, controlling “for own-vehicle weight, being hit by a vehicle that is 1,000 pounds heavier results in a 47 percent increase” in the probability of a fatal accident. The chance is even higher if the heavy car is an SUV, pickup truck, or minivan. (Taller vehicles tend to do outsize damage, too.)

The researchers then set out to calculate the value of the “external risk” caused by our heftier vehicles. First, they considered a scenario in which a driver chose between a car with the 1989 model-year average weight of 3,000 pounds or the 2005 weight of 3,600 pounds. The heavier car increased the expectation of fatalities by 0.00027 per car—27 deaths per 100,000 such vehicles. “Summing across all drivers,” they write, “this translates into a total external cost of $35 billion per year,” using the Department of Transportation’s value of a statistical life of $5.8 million. Judging against a baseline in which a driver chose the smallest available car, such as a Smart Cars, the cost is $93 billion per year. The price tag climbs beyond $150 billion per year if you include the cost of pedestrian and motorcyclist deaths and figure in multi-car collisions.

But this latest study hardly means an end to the debate. After all, vehicles have been getting larger and larger for decades but the overall number of deaths per vehicle mile traveled has been declining for at least as lon g. So how do the Berkley authors explain these contradicting trends?

The problem is that American roads consist of a mix of heavier and lighter cars, and the biggest danger is when they encounter each other. The authors write that relative weight is what is most dangerous in crashes. The recent vogue for lighter vehicles, driven in part by high gas prices and changing fuel-economy standards, has raised worries about the chance of more collision deaths. One study found that higher fuel-economy standards imposed in the 1980s led to 2,000 additional deaths per year. If Americans suddenly start buying many more ultra-light cars, it is not hard to imagine more deadly accidents as a result.

That’s a pleasant thought, isn’t it? The eternal bugbear of US automotive regulation, the tradeoff between safety and fuel economy, just won’t go away. So what’s the solution?

Given the relationship between big cars and bad accidents, it might make sense to make such cars more expensive to buy or drive. You could do this with insurance premiums, or lawsuits. But the economists suggest a gas tax, “because it is simple and because gasoline usage is positively related to both miles driven and vehicle weight.” They say it would take a 27-cent-per-gallon gas tax to account for the $35 billion per year in extra costs from heavier cars. (To account for the $150 billion in extra costs would require a tax of more than $1 per gallon.)

Notch up another, if somewhat more debatable, reason to increase the gas tax (as if we needed another).

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5 of 157 comments
  • Jaybread Jaybread on Jun 28, 2011

    Off course I like gas taxes, sales taxes, income taxes....it's nice to be needed. Capitalism increases the number of choices, this is not incompatible with the text book definition. No true monopoly could exist with out protection, at least that's what Uncle Milton taught me. That's why corporations invest so much in lobbyists...helps keep the wolves at bay. Why would commuting in an F450 make me a D-Bag? I don't block the left lane, I use my turn signal, and let old ladies cross the street. Such anger! BTW-F450's check in at closer to 4.5 tons full of fuel, not 3 tons. But I guess I'm being a D-bag by pointing that out.

    • See 1 previous
    • Pch101 Pch101 on Jun 28, 2011
      Capitalism increases the number of choices; You keep talking about "capitalism" as if that has some relationship to this topic. The topic is that two economists have drafted a working paper that concludes that SUVs create externalities. The ways that they explore for reducing those alleged externalities is by increasing taxes that would impact the demand for SUVs. They aren't talking about outlawing SUVs. They're talking about increasing the costs of ownership, so that they pay for the costs that they supposedly generate. If people want to own SUVs under this scenario, then they can increase their incomes, reduce their savings or divert spending from other sources. As is the case with a Ferrari or a 911, you can own one, but there's no Constitutional guarantee that you can afford to pay for it.

  • AJ AJ on Jun 28, 2011

    I'd rather get in a wreck while driving my wife's mid-size SUV then in my daily driver Civic.

    • SVX pearlie SVX pearlie on Jun 28, 2011

      I'd rather wreck in my 3500+lb E60 sedan than our 5000+lb W251 CUV, only because it's more likely that I'm the only family member involved. If it's just me alone in the car, then I'll choose to have the accident with the extra "crush space" and body steel all around, TYVM.

  • The Oracle I say let the clunkers stay on the roads.
  • Jpolicke Twenty-three grand for a basket case? And it has '66 wheel covers and gas cap so who knows what else isn't original?
  • Scott Can't be a real 1965 Stang as all of those are nothing but a pile of rust that MIGHT be car shaped by now.
  • 56m65711446 So, the engineers/designers that brought us the Pinto are still working at Ford!
  • Spookiness I dig it. The colors are already available on the CX-50. The terracotta is like a nice saddle brown. The non-turbo Carbon Edition has a bluish gray and a burgundy leather interior. A nice break from the typical relentless black and 50 shade of gray palette. Early CX-30's had some dark navy blue (armest, console, and parts of the door) but I guess that was just too weird and radical so they switched to all-black.I'd be fine with cloth in colors, leather is over-rated, but I'll never have an all-black interior in a car ever again.