By the time you finish reading this article, one American will likely die in an automobile accident. By the end of today, that number will reach around 100 and will end up well over 30,000 by year's end. It is almost certainly the case that you have known at least one of the 785,000 people who have died this way in the last 20 years. Sadly we both knew several.

In contrast, even if it took you a week to read this article, no American will likely have died from a terrorist act during that time. Including the 2,996 people who died on 9/11, only about 175 Americans have died from terrorism annually since 1995. If you exclude 9/11 that number falls to just 25 people per year, on average about 2 per month. It is extremely unlikely that many readers knew even one of these people.

Despite these facts, most people, including our elected officials, appear more concerned about the apparently very small risks associated with terrorism compared with the much higher risks of dying in car accidents. As University of Michigan psychology professor Richard Gonzalez and University of Chicago business professor George Wu point out in their research, "people tend to overweight small probabilities and underweight large probabilities." The sterility of academic research on risk sometimes allows people to dismiss its potential importance, but terrorist and road deaths, as well as the spending associated with reducing these events, provide a fruitful comparison for understanding the efficiency of government spending.

Let's compare how our government deals with these two problems. The war on terrorism has consumed nearly $5 trillion in tax dollars since 2001, about $183 billion per year. Even if you include 9/11 deaths, for every one American death due to terrorism, the U.S. government has spent about $1 billion.

One could argue that these funds have saved thousands or millions of lives from thwarted or deterred terrorist attacks, but we should remember the risk of dying from a terrorist was never very high. In the years leading up to 9/11 and before the war on terrorism began in earnest, the number of American deaths due to terrorism numbered fewer than 100 each year. Even if the war on terrorism had reduced these deaths to zero, which it hasn't, the cost would have been nearly $2 billion per life saved.

What about road safety spending? As far as we know, there are no reliable estimates on total expenditures on road safety measures. We do know that the total amount of construction spending on highways and streets has averaged about $75 billion per year in the United States during the past decade. What's more, fatal accidents amount to approximately $44 billion in work loss and medical costs, according to the Centers for Disease Control. The combined cost of fatal accidents and spending on highway and street construction amounts to much less than what is spent on the war on terrorism, even though road deaths annually account for at least 200 times more deaths than terrorism.

According to one study in Accident Analysis & Prevention, cost-effective road safety measures like improved intersection design, speed bumps and guard rails costing mere millions, not billions, of dollars per life saved can yield 50 to 60 percent reductions in deaths on the roads. In America, this equates to more than 15,000 fewer deaths each year. Moreover, simple reallocations in support of highway patrol divisions can significantly improve the safety of roadways. As Gregory DeAngelo and Benjamin Hansen note in their research published in the American Economic Journal, "A highway fatality can be prevented with $309,000 of expenditures on state police," which amounts to less than 1 percent of the spending per life lost in the war on terrorism.

The simple fact is the war on terrorism is a colossally disproportionate waste of scarce time and money. Shifting the money spent on wars in the Middle East and Department of Homeland Security to improved road safety would save tens of thousands of lives without any measurable impact on the risks associated with terrorism.

Robert Lawson holds the Jerome M. Fullinwider Endowed Centennial Chair in Economic Freedom at Southern Methodist University's Cox School of Business. Email: rlawson@smu.edu

Greg DeAngelo is an assistant professor of economics at West Virginia University. Email: Gregory.DeAngelo@mail.wvu.edu