Credit: Slug Signorino

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I’ve come across several references recently to the alleged fact that the introduction of federal automobile fuel efficiency standards in the United States has increased the number of automobile deaths. The only sources cited are “free-market” think tanks. Is there any empirical evidence for this claim? If the federal government banned small cars, would highway deaths drop?

—Collin Cain, Washington, D.C.

They might.

Ever since the feds established the first Corporate Average Fuel Economy (CAFE) standards in 1975, we’ve heard griping from automakers, car enthusiasts, small-government types, and some self-described safety advocates. The Competitive Enterprise Institute, a conservative public-policy organization, complains that “CAFE restricts the production of larger, heavier vehicles…[which are] safer than similarly equipped smaller cars.” The National Center for Public Policy Research takes a harsher view: “These federal rules are responsible for thousands of needless deaths and injuries.” The Heritage Foundation claims that CAFE contributes “to about 2,000 traffic fatalities per year.” Anti-CAFE folks often cite a 1999 USA Today report (“Death by the Gallon”) claiming 46,000 people had died up to that point as a result of smaller, CAFE-friendly cars—as they put it, 7,700 deaths per every MPG gained.

Are these claims true? We can quibble about the numbers and quarrel with the premises, but the answer essentially is yes—the drive to build smaller cars has resulted in more deaths due to auto accidents.

One of the first major studies on the subject concluded that a 500-pound weight reduction in 1989-model cars would result in 2,200 to 3,900 additional deaths over a 10-year span. A 1997 study for the National Highway Traffic Safety Administration (NHTSA) showed that a mere 100-pound weight reduction in passenger cars resulted in a fatality rate increase of 1.1 percent and an injury rate increase of 1.6 percent. A 2002 NHTSA review of research to date concluded that CAFE-driven weight reductions have cost as many as 1,300 to 2,600 lives per year.

Some CAFE advocates, while disputing the details, concede the core argument. A 1992 report by the National Research Council agreed smaller cars might mean more deaths, although the group felt the effect was likely to be small. The report noted that in other motor-vehicle policy decisions—notably raising highway speed limits and allowing right turns on red—added convenience was considered an acceptable tradeoff for increased risk, and therefore “concern for safety should not be allowed to paralyze the debate on the desirability of enhancing the fuel economy of the light-duty fleet.”

The reason weight reduction leads to more deaths is a matter of common sense and simple physics. Heavier cars tend to be larger, and larger cars contain bigger “crush zones,” which give passengers more time to decelerate as the car crumples in an accident. And all else being equal, the larger and heavier a car is, the stronger it’s likely to be structurally. But even if two cars in an accident are the same size, the heavier one generally fares better because it’s more likely to damage the lighter car or shove it into harm’s way than vice versa. People who buy SUVs often cite this reasoning—they’re looking out for their own safety. Problem is, they’re doing so at the expense of those riding in the lighter vehicles they crash into.

Which gets us to the heart of the issue. Ban small cars? Don’t be ridiculous, CAFE advocates say. We’d all be safer and use less gas to boot if we banned SUVs. A 2002 study of 84 cars, trucks, SUVs, and minivans conducted for the U.S. Department of Energy concluded that SUVs and pickup trucks had the highest combined risk of any vehicles—that is, risk to both their occupants and occupants of other cars. True, the average SUV protected its occupants better than the average small car. However, some midsize cars protected their occupants just as well as SUVs without unduly endangering the occupants of other vehicles. The study also found that the safest compact and subcompact cars were as safe for their drivers as the average SUV—and safer from a combined-risk standpoint.

Despite what some kibitzers suggest, the CAFE era has been a good one for road safety—the crash fatality rate has dropped fairly steadily since about 1980, continuing a trend going back at least 50 years. Why? Probably in large part due to the buttinsky regulations and tougher laws antigovernment zealots decry:

• Fatalities due to drunk driving have decreased, both in absolute numbers and per mile.

• Seat belts, now mandatory, are estimated to have saved more than 211,000 lives since 1975.

• Between 1987 and 2003, air bags prevented 14,000 deaths.

Face it: Saving lives and saving gas to an extent are contradictory goals; the best you can hope for is a reasonable compromise. Not to say things couldn’t be improved, but right now, judging from the numbers, that’s what we’ve got.

—Cecil Adams

Is there something you need to get straight? Take it up with Cecil on the Straight Dope message board,, or write him at the Washington City Paper, 2390 Champlain St. NW, Washington, DC 20009. Cecil’s most recent compendium of knowledge, Triumph of the Straight Dope, is available at bookstores everywhere.