Fuel efficiency kills people
Two-vehicle crashes
are the largest source of traffic fatalities, accounting for 43% of
traffic fatalities in 1999. Fatalities in car-to-car crashes have
sharply declined even while the number of cars on the road has
gradually increased. Car-to-car head-on fatalities dropped 35% in the
1980s and did drop another 25% in the 1990s. If one looks at fatalities
in new cars only, the decline is even more rapid-an 80% decrease for
1980-97! The consequences of car-to-car head-on fatalities have been
revolutionized by protection technology, motivated in part by the
standardized crash test. Seat belts and air bags are increasingly
effective in protecting occupants. Powerful computer-assisted efforts
also enable safety improvements in the design and manufacture of
vehicle structures.
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Light trucks
crashing with cars now cause many more fatalities than cars crashing
with cars. Collisions where trucks strike cars on the side are now the
largest cause of fatalities in two-vehicle crashes. Over two thousand
lives would be saved annually by establishing "compatibility" between
cars and light trucks. This means reducing the mass differential
between cars and those light trucks used as car substitutes by making
the heavier vehicles lighter. Compatibility in height and stiffness is
also required-for example, for the front of the striking vehicle
(truck) and the side of the struck vehicle (car). Compatibility
involves both vehicles: The lighter cars would not be made still
lighter, but would be made larger in selected ways.
Such changes can be
achieved with the help of mass-reduction technologies. First, the basic
structure of light truck car-substitutes that are now body-on-frame
would instead be unibody (like today's cars) or perhaps space frame.
Second, the use of lightweight materials (such as high- and
ultrahigh-strength steels, aluminum, and engineering plastics) would be
emphasized. Third, high-efficiency propulsion systems would be much
lighter. These technologies include: (1) small displacement engines
with a much higher ratio of power-to-displacement; (2) automatic
transmissions that function smoothly without a torque converter (with
sophisticated motor-shifted standard transmission or continuously
variable transmission); and (3) on-shaft starter-generators with a 42
volt (V) electrical system, enabling idle-off and other modest
hybrid-drive capabilities without a heavy battery.
There are also many
deaths in one-vehicle crashes-31% of all fatalities are from collisions
with stationary objects like trees, parked cars, and utility poles.
Fatalities in these crashes have also declined, perhaps for similar
reasons as the decline in car-to-car crash fatalities, although the
decline has not been as rapid. Progress could continue in the face of
mass (but not size) reduction because cars that are "overweight" for
their size do not appear to offer significant added protection.
Some 12% of
fatalities in cars and light trucks occur in "non-collision" events,
mostly rollovers following driver loss of control. The likelihood of a
rollover is increased by certain design features, such as high center
of mass, narrow track width, and softness of suspension with respect to
roll. The likelihood is also increased by a high load, like passengers
and luggage in an sport utility vehicle (SUV) with its high floor. The
historical correlation in cars of light weight with rollovers is not
inherent, but a matter of design. In new model cars, this correlation
has essentially disappeared. With rollover tests and standards, design
changes will also be made to reduce rollovers in light trucks.
In Europe, efforts
to develop extremely light/small vehicles (by U.S. standards) are
leading to the development of relatively effective protection systems
for that vehicle class, although it appears that the safety technology
may increase both cost and weight. The European studies we have seen
have not examined the option of maintaining or even increasing size
while reducing vehicle weight using new lightweight materials.
Our conclusions regarding the impact of reducing vehicle weight on vehicle
safety are:
(1) The high mass ratio of most "light" trucks over cars is an inherent
aspect of incompatibility in crashes. Reduction in the mass and other incompatibilities
of the light trucks would result in a major decrease in car fatalities and in
fatalities overall.
(2) Moreover, increasing size in selected ways, such as increased crush space
and stiffness at the sides, is likely to be a powerful technique for reducing
traffic fatalities.
In a nutshell, from a safety perspective the United States needs to resolve
the incompatibility of light trucks with cars and it needs to continue development
and adoption of powerful crash mitigation and avoidance technologies. Making
heavier vehicles lighter (but not smaller) and making lighter cars larger (but
not heavier) would not only increase safety but also increase fuel economy.
We project a fuel economy increase of over 50% in association with these safety
measures.
E.P.A. Blocks State Emission Rules
"The
Environmental Protection Agency on Wednesday denied California and 16
other states the right to set their own standards for carbon dioxide
emissions from automobiles," reports The New York Times.
"The E.P.A. administrator, Stephen L. Johnson, said the proposed
California rules were pre-empted by federal authority and made moot by
the energy bill signed into law by President Bush on Wednesday."
In "Leave Those Car Buyers Alone,"
Cato senior fellows Jerry Taylor and Peter Van Doren write: "Reducing
vehicle weight is the cheapest way to improve fuel efficiency, but that
would increase highway deaths, just as it has done in the past
according to a 2002 study by the National Academy of Sciences.
Reengineering cars will reduce automotive performance in ways that
car-buyers probably won't like while increasing automotive prices by as
much as $3,500 a car according to the same NAS study. Cross-subsidies
might be the most direct way to meet the standard, but that represents
a rather steep tax on people with large families, big dogs, and those
who for whatever reason need to haul around a lot of stuff -- not to
mention those who simply have a preference for zippy sports cars or
riding high off the road.
"So how does that square with claim that consumers win with more
fuel-efficient cars? Well, if all other things were equal, they would.
But all other things are not equal, and fuel-efficiency improvements
involve trade-offs that consumers are demonstrably not wild about
making. If they were, we wouldn't need a CAFE law in the first place.
The fleet would average 35 mpg now."
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