How speed limits can cost lives
by Gary M. Galles (associate professor of economics at Pepperdine
University in Malibu, Calif.)
(reprinted without permission from the Chicago Tribune, 2/8/93)
(copyright D.B.Johnson/L.A. Times Syndicate)

	Speed kills.  Everyone knows that (largely because the
government told us so).  And going faster burns more gas.  So slowing
drivers would be a great way to save lives and gas.  That was the
logic behind Congress' imposition of a nationwide 55-m.p.h. maximum
speed limit in the aftermath of OPEC's first oil price shock in the
early 1970s (over some very strenuous objections by many states,
especially in the West, which capitulated only under threat of losing
federal highway funds), a restriction relaxed to 65 m.p.h. for rural
interstates in 1987.
	The only problem with the federally mandated stay alive at 55
policy is that, as a result of the law of unintended consequences (a
government action intended to achieve one goal will have other,
unintended consequences as well), it may actually result in a greater
highway death rate than if states were free to set higher limits where
they deemed it safe, according to a just-released study.
	Charles Lave, an economics professor at the University of
California, Irvine, compared traffic death rates between those states
that increased their speed limits on rural interstates to 65, when the
federal government allowed it in 1987, with those that did not.  The
result was that, adjusted for other important determinants of highway
fatalities, such as seat belt laws and the number of vehicle miles
traveled, states that raised their limits to 65 saw a reduction of 3.4
to 5.1 percent on average (7 percent in California) in their highway
fatality rates.
	How could lower interstate speed limits lose lives?  It turns
out that there are at least three reasons, each apparently
unconsidered by Congress when the law was passed.
	First, enforcing speed limits far slower than most drivers
want to go on interstates requires a great deal of highway patrol time
and resources.  When higher speed limits are allowed on those
highways, some of that time and those resources can be devoted to
areas that have a greater impact on safety, such as more dangerous
roads (after all, interstates were designed to be safe at far more
than 55 m.p.h., at a time when cars were far less safe than today, but
the same is not true of other roadways) or programs to reduce drunk
driving (involved in just under half of all traffic deaths
nationwide).  Even if more speed on the interstates increased
fatalities, as long as more lives were saved by these same resources
devoted to other roads or other programs, as indicated by Lave's data,
higher interstate speed limits would actually save lives.
	Second, the faster you go, the less time you spend on the road
to cover a given distance.  This is an especially important factor in
less-populated regions of the country where longer trips are the norm.
Anyone who has ever driven alone a long stretch knows that the last
hour is by far the most dangerous one-- the one where you keep your
gritty-feeling eyes open only by alternating which one is open, by
playing that ridiculous alphabet game with car license plates, by
blaring your stereo and running the air conditioner on full blast and
similar tactics.  By letting drivers cut some of those dangerous last
hours off, a higher speed limit can save lives, especially for longer
trips.
	Third, it is the differences in speed between vehicles, not
just the average speed, that is the source of many highway accidents.
By raising the speed limit, the variance in speed between those who
seem to leave a sonic boom as they pass and those more law-abiding
citizens who feel compelled to stay at or near the legal limit can be
reduced, reducing the risk of accidents between them.
	As Professor Lave states in his study, the federal
55-m.p.h. speed limit was a failure as a way of saving energy (it
reduced gasoline consumption by only one-half of 1 percent, far less
than could have been achieved simply by keeping tire pressures at
their recommended level), and it's a failure when it comes to saving
lives.  He concludes it's time to abandon the federal role in setting
speed limits, enacted by a Congress full of rank amateurs in this
area, and let highway safety professionals and political
representatives in each state set their own speed limits.
	Setting nationwide speed limits to save lives seems like a
relatively straightforward proposition, compared to the far more
complex social issues our federal government is hip deep in.  But even
here the law of unintended consequences (operating through changes in
enforcement costs, length of trip and variance in speeds) has resulted
in its being a counterproductive failure, giving us the opposite
result from that desired while restricting freedom in the process.  As
we enter the Clinton era of activist government, this may serve as a
warning to the limits of that approach.

[END of essay]