While urban expressways carry most of the traffic and get most of the federal highway money, more people are killed on the less-traveled, less-funded rural roads.
"We're seeing fatality rates nearly double (that) on urban roads," said researcher Frank Moretti.
Transportation officials said the money is flowing to the roads more traveled.
"They're going to invest more of their resources in the urban area," said John Horsley, executive director of the American Association of State Highway and Transportation Officials and a former official of Kitsap County, Wash. "That's where the traffic is."
Moretti, with the business-funded Road Information Program, says many old highways are outdated.
"Rural roads initially were built to carry lighter traffic. They weren't built to the safety standards of urban roads," he told CBS News Producer Kevin Geiger.
Yesterday's back road is often today's commuter shortcut.
"Increasingly, a lot of rural roads are carrying suburban traffic as the population grows and people tend to spread out," he said.
Local officials argue that the high number of fatalities on rural roads poses a powerful argument for more federal money.
"Roads owned by local governments don't seem to be getting their share of federal highway dollars, even though statistics point out that those roads tend to have a higher rate of fatalities," said Bob Fogel, associate legislative director of the National Association of Counties, which is pushing for more federal funds for rural roads.
"Both the federal and the state governments are going to have to start to adopt programs that very quickly allow them to address these key safety problems," added Moretti.
A recent General Accounting Office report found that urban expressways got $80,900 in federal funds per lane mile in 1999, compared with $100 per mile for rural local roads.
At the same time, those rural roads owned by local governments recorded 4,758 deaths — a rate of 3.79 per 100 million miles traveled — compared with 1,354 deaths along urban freeways, a rate of 0.79 per 100 million miles.
Overall numbers showed the same trend, said the GAO, the investigative arm of Congress.
In 1999, roads passing communities of at least 5,000 people carried 1.6 trillion miles of traffic and recorded 15,816 highway deaths, a rate of 0.97 per 100 million miles. Rural roads overall had 1.1 trillion miles of traffic and 25,107 deaths, a rate of 2.36.
Idaho police, for example, have seen a steady increase in the number of highway deaths in the state.
"This area has a lot of scenery, lower populations and fewer towns, so driving gets mundane, routine and you let down your guard," Idaho State Police Lt. Eric Dayley said.
One reason for the higher fatalities is that motorists drive fat on those two-lane rural roads, said Lindsay Griffin, director of the transportation safety center at Texas A&M University's Texas Transportation Institute.
"You may not have as much traffic but you may have higher traveling speeds," Griffin said.
Also, these roads often are not built to modern safety standards. The lanes may be narrower, and there is no median to separate oncoming traffic. Some rural roads are being used as commuter routes as suburban sprawl moves farther out from central cities and congestion on major highways increases.
"Typically, they're either too narrow or the alignment really aren't appropriate for higher volumes of traffic," Moretti said. "The curves are too quick, and they really need to be re-designed so that they can carry higher traffic safely."
"The road historically thought about as a rural road is now becoming heavily traveled," Fogel said. "The road wasn't built to the standards needed for those purposes. Those roads are being worn down."
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