The Honorable Frank R. Wolf
Chairman, Subcommittee on Transportation
Committee on Appropriations
U.S. House of Representatives
Washington, DC 20515

Dear Congressman Wolf:

FUEL ECONOMY REGULATION AND VEHICLE SAFETY

From articles in the trade press, I gather that some Members of Congress are considering changes in legeslation to allow NHTSA to tighten fuel-economy rules in the years ahead. The Harvard Center for Risk Analysis has considerable expertise on these issues and thus I would like to offer some thoughts and materials for your Committee's consideration.

First, there is a well-documented history of CAFE regulation hurting motor vehicle safety by inducing a smaller fleet of passenger cars than otherwise would have been produced and sold to consumers. I have enclosed for your information an article I wrote with Robert Crandall of the Brookincs Institution in 1989 that quantified the adverse safety effects of CAFE (enclosure).

Second, there were legislative proposals in the early 1990's to raise CAFE standards significantly. At the time, I published a risk analysis in the peer-reviewed literature (enclosure) that projected how many additional deaths and injuries might result if CAFE standards were again tightened. These proposals were defeated in Congress, in part because of safety concerns. I urge your staff to read this paper because many of the key analytical considerations are relevant to today's policy debate about fuel economy regulation and safety.

Third, in the mid-1990's NHTSA performed a series of studies on the question of whether a smaller, lighter fleet of passenger cars and light trucks would harm vehicle safety. These studies were revised in response to technical comments by the Transportation Research Board of the National Research Council/National Academy of Sciences. The conclusion of these studies was that each reduction in vehicle size/weight is associated with a fleet-wide increase in traffic deaths and injuries, taking into account effects in both single-vehicle and multi-vehicle crashes. Our Center is currently using data from these studies to prepare updated estimates of the potential adverse safety effects of tighter CAFE regulations.

Fourth, I understand that the fuel economy of light trucks (vans, jeeps, pick-up trucks, and sport-utility vehicles) is a special concern. One of the most feasible methods to enhance the fuel economy of light trucks is to convert engines from conventional gasoline to diesel fuel. This is a strategy that is already used in Europe and is the subject of a new agreement between the European Commission and the European vehicle manufacturers to reduce carbon dioxide emissions. The diesel engine is significantly more fuel efficient than a gasoline-powered engine, and can be incorporated into new light trucks without any significant loss in vehicle size, weight, or safety. Unfortunately, recent California and EPA regulations on tailpipe pollution regulations, which may be more stringent than is necessary to achieve cost-effective pollution control, will make it difficult or impossible for even "green" diesel technology to be marketed in the USA. Fortunately, EPA is also calling for lowered sulphur levels in fuels, which may brighten the prospects of "green" diesel technology. I urge the Committee to consider whether our nation has thought seriously about the compatibility of EPA and NHTSA regulations as they relate to fuel economy, the diesel engine, pollution, and safety. A recent issue of our newsletter, Risk in Perspective (enclosure), highlights the tradeoff between fuel economy and emissions control.

Finally, a variety of news articles have suggested that light trucks may be less safe than passenger cars because light trucks are more "aggressive" in two-vehicle crashes than are passenger cars. This is a serious safety concern that is now being addressed by the motor vehicle manufacturers and NHTSA. Yet recent media coverage has missed a critical point about safety: in single-vehicle crashes, the type of crash that produces the largest share of fatalities, the extra size and weight of light trucks provides more safety to the driver and passengers of light trucks. Although this extra vehicle weight does impose additional risk to occupants of other vehicles in two-vehicle crashes, vehicle manufacturers are already taking steps to reduce the aggressivity of light trucks and enhance the crashworthiness of passenger cars.

In summary, I would like to express a concern that many policy discussions of fuel economy regulation do not include adequate appreciation of the potential adverse safety effects of a smaller, lighter vehicle fleet. More thought needs to be given to new policy approaches that promise simultaneous improvements in both fuel economy and safety. At the Harvard Center for Risk Analysis, we are exploring some ideas in this area. Indeed, one of my doctoral students, Mr. Edmond Toy, has a doctoral dissertation underway on these and related issues.

Thank you in advance for your consideration of these ideas and materials. Please do not hesitate to contact me if you should have any questions or desire additional information.

Sincerely,

John D. Graham, Ph.D.
Professor and Director

---

CVC home page

Back to last page

Top of this page

This page last updated: 5/24/00