The nation's infrastructure: Another victim of congressional gridlock?

When President Obama travels to New York Wednesday, the Tappan Zee Bridge just north of New York City will illustrate one of the nation's most pressing problems: a looming dropoff in transportation funding.

Twin crises are set to interrupt the construction boom that takes place each year during the warmer weather as states and cities set out to repair America's aging and ailing infrastructure. The most pressing is the drying up of the Highway Trust Fund, which the Department of Transportation predicts will be depleted by late August. As a result, the funding that states get from the federal government for highway projects - about 45 percent - will start to shrink.

Transportation Secretary Anthony Foxx warned reporters Monday that letting the account expire could lead to 700,000 Americans losing jobs in road work, bridge-building and transit maintenance.

"All of these types of projects may be delayed or shut down completely -- which means freight won't move, which means trade will slow, which means businesses won't hire. And, by the way, your morning commute will be longer because the roads you're driving on will crumble and no one will show up to fix them," Foxx said.

As if that wasn't crisis enough, the bill that governs all federal transportation policy, known as MAP-21, will expire at the end of September. But given that U.S. transportation policy doesn't come cheap, and the appetite for spending in Congress is nonexistent, an agreement will be card to come by.

"This may be the most dire moment the American transportation system has faced in decades," Foxx said.

The looming funding cliff couldn't come at a worse time. Last year, the American Society of Civil Engineers gave the nation's public infrastructure a D+ on their annual report card and estimated that $3.6 trillion in investment will be needed by 2020.

The coffers of the Highway Trust Fund have traditionally been filled by the federal gas tax of 18.4 cents per gallon. It was last increased in 1993, but a combination of inflation and the increasing fuel efficiency of cars driven in the U.S. has slowly eroded the fund over the years. Since 2008, Congress has transferred in $54 billion to keep it afloat, according to the Wall Street Journal.

The Congressional Budget Office (CBO) shows a steadily increasing gap between the amount of money paid out of the fund and what it brings in. Starting in 2015, there will be a shortfall that would grow to more than 80 billion dollars by 2022 if there is no solution.

A six-year reauthorization of the MAP-21, meanwhile, would cost almost $100 billion in new revenue just to keep up with the current spending levels on road and transit projects, the CBO projects.

One option to raise more revenue would be an increase in the gas tax, a move that has been supported by organizations ranging from the Chamber of Commerce to the AFL-CIO to AAA. But a tax increase that would affect such a broad swath of Americans is a political nonstarter, especially so close to an election year. Both the White House and Republican leadership in Congress have ruled that out.

So what would the White House do? The administration recently put forward a four-year, $302 billion transportation plan that would be funded in part by the existing gas tax, and in part by vaguely-defined "pro-growth business tax reform." The proposal actually increases both highway and transit funding, and allows states to charge tolls on interstate highways as a way to raise funds.

At the time President Obama first laid out the plan in February, House Ways and Means Chairman Dave Camp, R-Mich., rolled out a comprehensive tax reform plan that includes an eight-year, $126.5 billion investment in the Highway Trust Fund. But lawmakers have already thrown cold water on the idea of embarking on a major tax overhaul in 2014.

There was a step forward in the Senate this week: Sens. Barbara Boxer, D-Calif., and David Vitter, R-La., the chairwoman and ranking member of the Environment and Public Works Committee, put forward a bipartisan six-year transportation bill which maintains current spending levels at about $105 billion per year, plus inflation. The committee will begin consideration of the bill in a hearing Thursday. The House has not yet released its own proposal.

Without Congress, there's little the administration can do but sound the alarm. Foxx acknowledged this week it will be a long haul.

"This is going to be a nine-inning game," he said. "It's not going to get solved in the first inning."