Monday, September 26, 2005

Fuel Economy and Safety

Karen Lundegaard has an intereting article today in the Wall Street Journal about new thinking about fuel economy and safety.

The story presents a graph from the EPA showing fuel economy over time for cars, trucks, and then their combination. It makes the point well from an earlier discussion of the CAFE standards (here, here, and here). Even though fuel economy per vehicle may have been flat to increasing for both cars and trucks, the shift of more drivers into the less efficient trucks has caused the overall fuel efficiency to fall.

The main new point in the article is to point out that some new research takes issue with the presumption that improvements in fuel economy would come at the expense of safety:

For decades, whenever the federal government leaned on auto makers to improve fuel efficiency, the industry had a ready response: Research showed that lighter, more fuel-efficient vehicles weren't as safe as their heavier, gas-guzzling cousins. Even shedding as little as 100 pounds could lead to a serious increase in traffic fatalities.

The result has been a virtual standstill in fuel-economy improvements for cars, trucks and sport-utility vehicles over the past 20 years.

Now a wave of new studies and technologies -- strong, light materials, better airbags and smarter designs -- are beginning to break the logjam. The upshot: A big shift in government thinking that is paving the way for regulators to revamp fuel-economy rules for SUVs and pickup trucks for the first time in three decades.
I'm glad for the use of research on the other side of a long-held presumption, but I'm not sure the article gets the argument right. Later, we have:

For years, the accepted wisdom in the car industry held that, all things being equal, heavier vehicles are always safer when two vehicles crash. New studies highlight how other factors -- including a car's size, body design and advanced technology -- can do much to counteract the weight issue.

The newer studies also have homed in on the downside of weight: While a heavy vehicle protects its occupants in an accident, it inflicts more damage to those it hits. That means reducing the weight of the biggest vehicles could yield dividends in both fuel consumption and safety.

All of this has contributed to a rethinking of the fuel-economy regulations from the National Highway Traffic Safety Administration. Last month, NHTSA crafted new "Corporate Average Fuel Economy" rules, or CAFE, for light trucks that aim to balance safety and fuel efficiency. The old rules set an average weight target for an auto maker's entire fleet of cars or trucks, encouraging car makers to sell lots of small fuel-efficient vehicles at sometimes unprofitable prices, so they could keep selling their more profitable gas guzzlers.

The article fails to recognize two issues. First, there is a big difference in safety risks that a vehicle poses to its own occupants and the risks that a vehicle poses to occupants of other vehicles. There is a compelling reason for the government to be involved in the latter, far more than would exist for the former. Without government involvement, drivers of heavier vehicles would not bear the costs they impose on other drivers. (It's not clear that they do so now, apart from states without no-fault insurance requirements.)

Second, the flaw in the old system is the presence of multiple categories for fuel economy standards, with lower standards for some groups. That remains in the new system and can be expected to have the same consequences for fuel economy. Exactly what has changed that would arrest the slide in fuel economy shown in the graph above? Only the increase in the standard for trucks as a whole--not the presence of categories.

Consumers can make their own choices about how much safety they want in their own cars. The government can confine itself to providing accurate information about safety. The continued commingling of irrelevant own-occupant safety concerns with legitimate concerns about fuel economy makes the policy less useful than an ideal CAFE or a gas tax.

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Robert Schwartz said...

Patrick Bedard is my favorite writer on topics automotive. He wrote an essay a couple of years ago: "Funny how four doors reduce your rollover risk."

He was discussing the flaws in NTHSA's rollover rating system (since replaced), but I think he makes the point that a lot more goes into safety than raw vehicle characteristics. Here is a sample:

"Everywhere I look, I see that two doors, more than any other indicator, mark a rollover killer. We all know why some choose a two-door instead of the handier four-door. It's the anti-fuddy-duddy statement (I've been through that phase myself). And those folks intent on being unfuddy usually show us in other ways, too; some that require staying out into the risky hours of the night."

"From the HLDI tables, I conclude that any car with "sport" in its name — sports car, sports coupe, sport-ute — has a high rollover risk. Personally, I fail to see the "sport" in a crate-shaped high-rider, but market researchers assure me that buyers of sport-utes and sports cars are very similar in psychographics. Two-doors and these "sport" cars share a common trait — they have high death rates in single-vehicle crashes, higher than in vehicle-to-vehicle crashes and high in absolute terms. Four-doors (also vans, minivans, and station wagons) are the reverse, with low single-vehicle death rates."

"Single-vehicle crashes begin with the vehicle leaving the road (if it stays on, it hits another vehicle or there's no crash). Rollovers also begin with the vehicle leaving the road. Even NHTSA admits this is true in "more than 90 percent of rollovers." The driver loses control, falls off the road, then "a ditch, soft soil, curb, or other tripping mechanism usually initiates the rollover." There is wide agreement that SUVs don't merely flop over in normal driving. What they have is a falling-off-the-road problem, a problem shared with a broad class of two-doors chosen for Hey, look at me! reasons. NTHSA's rollover stars point the finger at the tall vehicles when they should be pointing to a class of drivers who can't stay between the ditches."

I have looked at some of the statistics he discusses. Conventional Vans and Pick-up Trucks share chassis and running gear. Why does the former category have a much lower accident rates than the later? Could it be that they are favored by older folks, while the young cowboys drive pick-ups? Now that SUVs have morphed into mom-mobiles, we would expect their raw accident totals to be fairly low. Using those figures to determine energy policy is really kind of useless.

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