By Daniel K. Benjamin
A rise in seat belt usage, combined with campaigns against drunk driving, helped reduce highway fatalities in the United States by about 20 percent from the mid-1970s to the mid-1990s. But since 1998, highway fatalities have been rising. Recent research suggests that some of this rise is due to the proliferation of light trucks on America's roads (White 2004).
SUVs, pickup trucks, and vans are more likely to be involved in crashes than are cars, and these crashes are more likely to result in fatalities and serious injuries. Thus, as light trucks have grown from less than one-fifth to more than two-fifths of the U.S. vehicle population, they have put upward pressure on highway fatalities. For every one million cars replaced by light trucks, there are 60 to 70 additional highway fatalities each year. There are now nearly 80 million light trucks on the road, so the potential carnage is considerable.
One reason people drive light trucks is the sense of safety such vehicles offer their occupants. Light trucks are heavier and higher than cars. They are also more rigid, which makes them absorb less force from a crash and transfer more to whatever they hit. While these characteristics of light trucks may help protect their occupants in the event of a crash, they also make these vehicles deadly for occupants of cars and for motorcyclists and pedestrians. Michelle White finds that, overall, for each fatal crash that occupants of light trucks avoid, at least 4.3 additional fatal crashes involving cars, pedestrians, or motorcycles occur. On balance, the result is more deaths on the highways.
It is true, given that you are in a wreck with another vehicle, your chances of being killed are cut by about one-third if you are in a light truck. Nevertheless, the characteristics of light trucks that serve them well in collisions with cars do little good when they are up against a bridge abutment. These characteristics may even make light trucks more deadly when they leave the road, because they are more likely to roll over. Thus, White finds, if you are in a single vehicle crash, your chances of dying are actually about 16 percent higher if you are in a light truck.
In addition, because light trucks do tend to confer safety in crashes with cars, light truck operators drive more aggressively, resulting in higher accident rates for light trucksâ€”about 45 percent higher for two-vehicle crashes and 31 percent higher for single vehicle accidents. Between their higher fatality rate in single vehicle crashes and their higher overall accident rates, SUVs and other light trucks are actually more deadly for their occupants than are cars.
This is not the first study to examine the safety of light trucks for their occupants and the impact of these vehicles on other motorists. Should we pay more attention to this one? The answer, I think, is "yes." Partly, this is because White has accounted for the aggressive behavior of light-truck drivers. In addition, White uses crash-by-crash individual data on almost 200,000 accidents, something never before done in an analysis of this type. Thus, she can control for confounding factors that help determine the incidence and lethality of vehicle crashes. These include weather conditions, speed, and road type, the age and sex of the driver of each vehicle, and whether police judged the behavior of the driver(s) to have been negligent (as when alcohol consumption is involved).
One question that remains is what-if anything-should be done about the higher carnage associated with SUVs, pickup trucks, andâ€”yesâ€”minivans piloted by soccer moms. White argues that our legal system should be reformed to induce operators of light trucks to drive in a way that accounts for the damages they inflict on others. For example, she suggests that speed limits be lower for light trucks and that the owners of these vehicles be required to carry more liability insurance.
Oddly, what White does not consider is why we have so many more light trucks on the road now than we did 25 years ago. As readers may recall, I reported in June 1998 on research showing that about 60 percent of the growth in the light truck population has been due to the Corporate Average Fuel Economy Standard (CAFE). This federal regulation, which mandates minimum fuel economy standards for new vehicles, has promoted the proliferation of SUVs and the like, because of the more stringent fuel economy standards it imposes on cars compared to light trucks (Godot 1997). If one is concerned about the hazards of pickup drivers who speed, the simplest first step would be to repeal the CAFE standard. This would not merely get the federal government out of the fuel economy business, it would mean that pedestrians, motorcyclists, and drivers of cars would have a better chance of getting to work in the morning. In the meantime, I'll simply assume that the Hummer next to me intends to change lanes whether I get out of its way or not.
White, Michelle J. 2004. The "Arms Race" on American Roads: The Effect of Sport Utility Vehicles and Pickup Trucks on Traffic Safety. Journal of Law & Economics (October): 33-55.
Godot, Paul E. 1997. The Regulation of Fuel Economy and the Demand for "Light Trucks." Journal of Law & Economics (October): 495509.
Daniel K. Benjamin is a PERC senior fellow and professor of economics at Clemson University. This regular column, "Tangents- Where Research and Policy Meet," investigates policy implications of recent academic research. He can be reached at: firstname.lastname@example.org