raffic jams are a nuisance, but they are more than that. Studies have shown that compared with people who walk or take public transportation to work, people who face protracted commutes in heavy traffic are more likely to experience high blood pressure. They have more frequent disputes with their coworkers and families. They suffer more frequent and more serious illnesses. And they are more likely to experience premature deaths.

Traffic jams are also getting much worse. A recent study by Texas A&M University, for example, reported that Americans spent three times as many hours stalled in traffic in 1999 as they did in 1982.

Although increased traffic congestion stems from many familiar causes (like population growth, cheap gasoline prices, increased urban sprawl and failure to invest in public transport), it is also the result of another factor that has received little attention — increased inequality in income and wealth.

The basic mechanism at work is something we may call the Aspen effect. Wealthy residents have long since bid up real estate prices in Aspen and other exclusive resort communities to levels that virtually exclude middle- and low-income families. Most of the people who provide services in these communities — teachers, policemen, firemen, laundry and restaurant workers — must therefore commute, often at considerable distance. As a result, all roads into Aspen are clogged morning and night with commuters, many of whom come from several hours away. "Greater Aspen" now has a radius of more than 50 miles!

Traffic congestion has been getting worse in part because during the past 20 years much of the United States has become more like greater Aspen. Since 1980, the inflation-adjusted incomes of the top 1 percent of families have more than doubled, while the corresponding growth for the median family has been less than 10 percent. During that same period, families in the bottom 20 percent actually saw their incomes fall in real terms.

As a result of these changes, residential patterns have become much more stratified by income. The effect has been more pronounced in some communities (the San Francisco peninsula, Austin and Seattle) than others (Chicago or Philadelphia). But the direction of change has been the same almost everywhere, and it has contributed to the rise in traffic delays.

The current policy agenda in Washington not only promises little relief for harried commuters, but is likely to make matters worse. Start with the tax cut. In the proposed $1.35 trillion reduction, 40 percent of the benefits would go to families in the top 5 percent. By making the income gap greater than it is already, this measure is likely to push low- and middle-income families even farther from their jobs, thus increasing the length of their commutes. Granted, the Aspen effect probably would not make anyone's list of the 10 most important reasons for opposing the tax cut. But it's yet another drawback to the Bush proposal.

Tax cuts would also put more pressure on already overcommitted government budgets, making it all but impossible to launch significant new urban transit programs in the next decade. And prospects for curtailing traffic congestion are further dimmed by the Bush administration's denial of any legitimate national interest in energy conservation. "The American way of life is a blessed one, and we have a bounty of resources in this country," said Ari Fleischer, the president's spokesman. "The American people's use of energy is a reflection of the strength of our economy, of the way of life that the American people have come to enjoy."

Our country does have a bounty of resources, but that doesn't eliminate the need to make intelligent decisions about how to use them. Traffic jams make life miserable for the rich, as well as for low- and middle-income families. They are neither an essential component of the good life nor inevitable. They can be greatly curtailed by smart public policy.