Continued: Judith Rodin: Gas-tax talk drives a necessary conversation

All the federal gas-tax talk has stirred up a storm. Whatever you think about the candidates' proposals, however, their debate has illuminated an urgent reality: If the U.S. government continues with its current transportation policies, it will undermine the social and economic security of our workforce and accelerate global climate change. We must chart a new course, rebuilding America's overburdened and, in many cases, obsolete transportation infrastructure while addressing these two 21st-century imperatives.

The good news is that we can tackle these challenges head-on -- with immediate benefits for our lagging economy. In the short term, "fix it first" strategies can repair existing infrastructure rather than beginning new construction, thus containing our carbon footprint. The Economic Policy Institute, for example, determined that, within 90 days, repair work could begin on 6,000 structurally deficient bridges across the country for about $30 billion, creating hundreds of thousands of jobs.

Over the long run, policymakers must also develop a more comprehensive plan. This is heavy lifting, and we're just getting started. The Brookings Institution's Metropolitan Policy Program, the Regional Plan Association's America 2050 initiative, the Bipartisan Policy Center and others are framing a national infrastructure vision. Pennsylvania Gov. Ed Rendell, California Gov. Arnold Schwarzenegger and New York Mayor Michael Bloomberg just launched Building America's Future, a nonpartisan coalition focused on advocating best practices and new ideas. And Washington recently, public officials and business, labor and civic leaders from across the country gathered for a summit, Rebuilding and Renewing America, to draft a blueprint for 21st-century investments.

Just how dire are the risks? The collapse of the Interstate 35W bridge in Minneapolis last August points to a fundamental crisis. Transportation systems and structures are outmoded and stressed beyond their capacities. This is not an abstraction; we suffer the consequences during our commutes every day. Traffic congestion in 2005 drained $78 billion from our economy, according to Texas A&M's 2007 Urban Mobility Report, adding 4.2 billion hours to Americans' commutes while wasting 2.9 billion gallons of gasoline.

Another critical danger is environmental. Today, the transportation sector consumes 90 percent of the United States' imported oil while producing one-third of the nation's greenhouse gas emissions -- and one-twelfth of the world's. Yet the federal government clings to a backward funding formula: The more a state's residents drive, the more money that state receives. In fact, projected increases in automotive travel will release so much greenhouse gas by 2020 that environmental protections achieved through higher gas-mileage requirements and anticipated advances in low-emissions fuels will be completely negated.

A less visible danger is economic. Transportation costs, now the second-highest household expense, are pricing families out of the American dream -- preventing them from saving, buying homes or investing in their children's educations. A 2006 Center for Housing Policy report indicated that working families in large metropolitan areas spend nearly a third of their incomes on transportation. A study by the American Public Transportation Association clarifies the connection between these challenges and the country's critical need for investment in mass transit: Two of every three regular users of public transportation earn less than $50,000 a year. The federal government, meanwhile, directs only one of every five gas-tax dollars to automobile alternatives.

As we look to the future, we must expand affordable, accessible and environmentally sustainable transportation options: high-speed and light rail, rapid and mass transit, and walkable, bikeable streets. Washington must provide new incentives for states and cities to promote greener land use, cleaner cars and decreased automotive dependence.

Fortunately, an extraordinary opportunity is on the horizon. Regardless of who wins in November, the new president and Congress will come to a crossroads when the highway bill is up for reauthorization next year. We must prepare to seize this moment by investing now in the search for solutions.

A half-century has passed since President Dwight Eisenhower signed the legislation establishing the United States' interstate highway system. That was among the most daring ideas of its time. It was a road map for the infrastructure that enabled 50 years of unrivaled economic prosperity and opportunity. Today, we must again dare to think and act boldly, but in a different way, because the world has dramatically changed.

Judith Rodin, president of the Rockefeller Foundation, wrote this article for the Washington Post.