When I drive that slow you know it's hard to steer
And I can't get my car out of second gear
What used to take 2 hours now takes all day
It took me 16 hours just to get to LA
Gonna write me up for 125
Post my face Wanted: Dead or Alive
Take my license all that jive
I can't drive 55
—"I Can't Drive 55,"?
Rock star Sammy Hagar is on to something. The 55-mile-an-hour national speed limit is a terrible idea. Though public opinion polls have 70 percent of Americans saying that they support this 11-year-old law, not since the dark days of Prohibition has a government decree met with such widespread disobedience.
To the Washington establishment, however, the 55-mile-an-hour speed limit has become something of a sacred cow. Yet its genesis was far from divine. I know—I was there, as a special assistant in the US Department of Transportation. The limit was a product of the Emergency Conservation Act of 1974, a hastily written response to "the energy crisis." The Department of Transportation was thrashing about, looking for energy-saving ideas, and hit upon a nationwide reduction in the speed limit.
Quick studies were done to figure the energy-saving potential of speeds of 40, 50, 55, and 60 miles an hour for both cars and trucks. Not surprisingly, fuel savings increased as speeds decreased. Going for the middle of the range, the original proposal called for 50 miles per hour for cars and 55 for trucks. The higher speed limit for trucks recognized the substantial impact of slower speeds on trucking costs, as well as studies presented by truckers' organizations claiming that trucks use less fuel at 55 than at 50 because of their transmission design.
The prospect of a more lenient standard for trucks caused quite a furor, particularly after syndicated columnist Jack Anderson suggested that maybe the trucking lobby had cut some sort of deal with the Department of Transportation. The atmosphere thus poisoned, putting both cars and trucks at 55 became an act of political compromise. And so it was that, although speed limits on the interstate highway system had previously been left up to the states, we came by a nationwide speed limit of 55. Any recalcitrant states wouldn't get their usual ration of Highway Trust Fund moneys, said the law passed by Congress, and soon every state had fallen into line.
The Department of Transportation had estimated the potential fuel savings from this law at about 200,000 barrels of petroleum per day, or about 1 percent of US petroleum consumption at the time. Subsequent studies on the energy-saving effects of 55 have been inconclusive, largely because it is difficult to separate out other causes of reduced gasoline usage, such as reduced travel and a shift to smaller, better-mileage cars. But it doesn't matter; the fuel-saving argument has receded as the energy crisis has become a dim memory. Now, the case for 55 rests on an entirely different assertion—that 55 saves lives.
In the early days of the law, highway fatalities did decline, though it's hard to tell just how much of the reduction can be attributed to the new speed limit. In fact, in recent years fatalities have continued to decline even though average speeds (what people actually drive, not the posted limit of 55) have been inching upward.
All things being equal, however, it's a pretty safe bet that a vehicle hitting another object is better off doing so at 55 than at a higher speed. And a vehicle traveling 45 is even better off, a vehicle traveling 35 even better, and so on. Think of all the lives we'd save if we just abolished cars!
Even the most ardent safety advocate will agree that at some point a trade-off must be made between potential accident reduction and the smooth, efficient flow of transportation. And once the necessity of such a trade-off is conceded, the problem becomes finding the speed at which maximum public benefits are realized. But the transportation bureaucrats don't know and never have tried to find out where that point is.
If 55, pulled out of a hat in 1974, is the correct speed, it would be a miracle. Perhaps the optimal speed is 63.5 miles per hour or 47 or even 75. We don't know. Such a calculation would be exceedingly difficult, as well as very expensive. The costs and benefits involved hinge on the value of time and the value of a life saved. Both of those measures come down to a host of value-laden questions that people would hardly be satisfied having traffic engineers or economists trying to resolve.
But the difficulty of getting the number right does not excuse accepting a random number. If the current speed is too high, there are lives to be saved at an acceptable trade-off. If it's too low, as Sammy Hagar and a whole lot of American drivers have concluded, substantial economic benefits are being forgone. But the lack of any studies doesn't stop the pro-55 crowd from speaking that number in hushed, reverent tones.
Supporters of 55 were heartened by a recent much-heralded study by the National Academy of Sciences (NAS). Congress, reacting to the increasingly embarrassing level of (non)adherence to 55, and hoping to avoid having to actually withhold money from offending states, asked the NAS to study the benefits of the national speed limit. The NAS. however, sensing a threat to its reputation for independence and integrity, interpreted "benefits" to mean both costs and benefits.
The Academy's study merits close inspection. Although it did little new research, the NAS panel sifted through all available evidence on 55 and produced a comprehensive and scrupulously detailed report. Congress certainly got what it wanted from the study—media headlines picking up on its main recommendations all reported that these distinguished scholars had concluded that 55 be retained. Yet the Academy's findings were not quite that simple.
The NAS recommended that 55 be retained "on most of the highways now posted at 55" but conceded that the study committee disagreed over whether or not the limit should be universal. And despite the NAS's cautious recommendation, the report contains lots of material that will prove more useful to opponents of 55 than to proponents. Key NAS findings include:
• Faced with the possibility of losing federal highway funds, the states have focused their traffic enforcement efforts where they count statistically—catching a hefty quota of speeders—rather than where they have the biggest safety effect. (So safety is actually put on the back burner by the 55 policy.)
• To make it appear as if they are complying with the law, the states engage in statistical manipulations that "do not appear fully warranted." (Put less delicately, the states cheat.)
• The chief flaw with 55 is that it sets one blanket speed limit for vastly different highways (a policy that any road engineer will tell you is foolish).
And here's a fascinating point made in the report: it is the variation in vehicles' speeds, more than their absolute speeds, that determines how safe a road is to travel. In an excellent appendix to the NAS report, Prof. Charles Lave of the University of California at Irvine presents the results of a statistical analysis of the relationship between speed and the fatality rate. There is none. There is, however, a significant relationship between speed variance and the fatality rate.
This speed variance finding may explain why automobile fatalities have dropped since the 55 limit was imposed. Lowering the limit pushed those who normally traveled much faster down to speeds close to 55, while those who usually traveled at 55 continued to do so. This resulted in more vehicles traveling within a small range of speed—and thus safer roads. It makes sense: when most vehicles are moving at about the same speed, they are less likely to bump into one another. With this in mind, the Academy report noted that it may be relatively unimportant if the average speed is a bit higher or lower than 55, as long as all the traffic on a particular road moves along at about the same speed.
On more legalistic grounds, opponents of 55 commonly argue from "state's rights" principles that it is outside Congress's legitimate federal authority to set speed limits for the states. Indeed, Congress seemingly wrote the law with an eye to this issue.
The 1974 Act did not technically set a national speed limit. What it did was arrange to withhold Highway Trust Fund revenues from the states unless they set their speed limits at 55. (The same tactic is now being used to "encourage" states to increase their legal drinking ages to 21 by October 1, 1986.) Thus it was federal financial blackmail and the dependence of the states on money from Washington to maintain the interstate highways that gave Congress the de facto power to force us all to drive 55.
In any event, Congress couldn't set a national speed limit for a very simple reason—the federal government owns only a very few roads located on federal property (roads on military bases, for instance). The vast majority of the nation's highways belong to the states and other levels of government or to quasi-public agencies. The power to set speed limits on roads comes with ownership. So the only way the feds could get a national speed limit was by using the carrot and stick of federal lucre—and it worked.
This was only the latest in a long list of things that the states have to do to get highway tax money back from Washington, even though this money is ostensibly "held in trust" for the states. In this case, Washington's bark seems worse than its bite. No state has ever actually had its highway money cut off. Instead, the criteria used to determine states' compliance have been revised downward rather continuously. Taking states' money away is a political hot potato that Congress won't touch. In 1981, for example, the percentage of traffic that states are required to keep at 55 in 55-mile-per-hour zones was slashed from 70 percent to 50 percent. (Even so, noted the NAS study, 37 states would be out of the money if not for "dubiously valid" statistical adjustments.)
Though the Academy did not attempt a rigorous cost-benefit analysis of the 55-mile-an-hour speed limit, it did put forth some interesting numbers on the subject. Those, for example, who hope to exempt various rural highways from the law should be heartened. The NAS noted that the costs of 55 in terms of lost time are much greater on rural interstate roads, which constitute the main intercity road system in the United States, than on other highways. For instance, while on the average 55 saves one life for every 25 years of driving time lost, on rural interstates that ratio declines dramatically—to one life saved per 100 years of time lost. Why are rural interstates so adversely affected by the national speed limit? Because these roads are generally built to the highest engineering standards and have relatively low traffic volumes, considering their capacity.
A sensible highway policy would take road quality and capacity differences like that into account. You don't have to be a civil engineer to know that there are some roads where 55 is a snail's pace and others where doing 55 is best left to Indy 500 drivers. Speed limits should not depend on the arbitrary whims of Washington bureaucrats. Rather, given the goal of safe, efficient transportation, four principal factors—road design, volume and mix of traffic, terrain and weather, and age and maintenance condition—should determine how fast vehicles can drive on different roads.
As with most things, road design has evolved over the years. Early turnpikes and interstates reflected the state-of-the-art knowledge of the times, but they are well behind current standards. Even so, most of the early interstate system was designed for speeds well in excess of 55. Design knowledge today is capable of producing highways constructed for even faster speeds.
Traffic conditions are the most obvious determinant of safe speeds. More is involved here than just monitoring traffic jams. A wise highway policy would also consider traffic volume in relation to road capacity and the "mix" of traffic—how many cars, buses, trucks, mopeds, or whatever use the road.
Anyone who's ever driven through a snowstorm realizes that weather conditions often dictate the proper speeds. Areas where snow, fog, heavy rains, ice, or hazardous terrain are common should have their speed limits adjusted accordingly.
As the interstate highway system approaches its 30th birthday, age and maintenance become important factors in determining the correct (or at least more correct) speed limits on many highways. Newer roads, and those recently rebuilt or repaired, can support much higher speeds than pothole-plagued highways.
There are other factors that a common-sense speed policy would take into account—how experienced are the drivers who use a certain road, in what condition are most of the vehicles that travel that road, and what sorts of activities occur adjacent to the road.
In addition, junking 55 would "unfreeze" highway technology that has languished since 1974. The history of transportation technology is the search for greater speed at decreased cost in resources, safety, and investment. This search has been stifled over the last 11 years by the 55-mile-an-hour speed limit, to the detriment of us all. It is as if the government had decreed in the '50s that airplanes were going fast enough and that no aircraft could surpass the speed of the DC-6. What a world of benefits would have been lost!
The case against 55 is overwhelming, but help from our legislators in Washington does not appear to be forthcoming. The 1980 Republican platform pledged to seek repeal of 55, but the Reagan administration has made precious little headway in effecting repeal or even modification. There has been speculation that one of the western states that so strongly oppose the national speed limit may take matters into its own hands by repealing its state law complying with the 55-or-else mandate, daring the federal government to cut off its highway funds. (And in fact, Arizonans are currently gathering signatures to force a statewide vote on 55.) Until then, millions of American motorists will continue to disregard this bothersome and paternalistic law.
Alan E. Pisarski is a transportation consultant based in Washington, D.C. He served on the 1980 Reagan-Bush transition team.
*Reprinted by permission. Copyright © 1984 by Warner Bros. Music Corp. & The Nine Music. All rights reserved.