LAS VEGAS - The Hoover Dam, one of the world's great engineering feats, is marred by roads with traffic so jammed along the Nevada-Arizona border that it tells a different story about the political will to maintain 21st century infrastructure.

The road leading to the dam cannot accommodate the torrent of tourists and spills them into the overwhelmed little town of Boulder City. Nevada lawmakers are trying to find a private company to build a $400 million bypass because the state can't afford it.

The phrase "you can't get there from here" is increasingly apt nearly everywhere one turns. America's roads, highways, bridges and transit systems are falling apart. Even those not in disrepair are often so crowded that a horse and buggy might seem faster. Cities and suburbs are outgrowing their infrastructure far faster than local governments can find the money to fix them.

While the problem is plain to all, the money and the political will to fix it isn't there.

Two congressionally mandated commissions and a slew of experts and committees have said the nation needs to double, even quadruple, what it spends each year to maintain and repair its aging transportation infrastructure and expand to accommodate population growth.

So there's the rub. No one likes traffic jams and potholes. No one wants people to die because an unsafe bridge has collapsed. But raising federal gas and diesel taxes or boosting tolls and fees isn't popular, either.

Pew Center polls in the last year show that 67 percent of those questioned said their state should not cut money for roads and public transit to balance its budget. But only 38 percent want federal spending increased and only 27 percent favor an increase in the gas tax that often pays for it.

At the same time, three-quarters say more spending on roads, bridges and other public works would help create jobs.

"The American public has turned selfish. They don't really want to invest in this stuff," said Robert Atkinson, a technology think tank executive who helped lead one of the federal transportation commissions. "It's akin to leaving your house to your kids when you die without fixing the roof because you wanted to spend the money instead on Florida vacations."

In Delaware, officials have delayed dozens of capital projects, but still expected a $21 million shortfall in the state's transportation trust fund this summer. The deficit is seen as growing to $1 billion by 2016.

In Texas, a committee recently declared the highway system inadequate and warned lawmakers that congestion would worsen without money for road improvements. Gov. Rick Perry's plan for a toll road across the state was abandoned in the face of uproar from ranchers whose land would be seized to build it.

In Pennsylvania, 5,906 bridges, or about 27 percent of the state's total, are graded structurally deficient, the highest rate in the nation, according to the Washington-based policy group Transportation for America.

The emergency closure this month of the 50-year-old Sherman Minton Bridge, one of three spans that connect southern Indiana and Louisville, Ky., has snarled the daily commute for tens of thousands of motorists. Officials found cracks in the steel span, raising safety concerns. The two states have struggled for years to find the money to build two more bridges.

Maryland business leaders persuaded the governor and lawmakers to spend more on road construction after a state commission found nearly $1 billion in transportation dollars had been diverted to the general fund budget.

In Georgia, lawmakers approved legislation to allow 12 regions around the state to ask voters next year whether to raise their sales tax by a penny per dollar to pay for an approved list of transportation projects. Officials in the 10-county Atlanta region recently endorsed a $6.14 billion draft list of transportation projects, from light rail to new highways, to ease congestion that's among the worst in the nation.

The consequences of inaction are severe.

Atkinson's commission forecast "unimaginable levels of congestion" in the coming decades. Safety will be reduced. Goods and services will cost more. The quality of life will be eroded, and the nation's economic competitiveness diminished, the commission predicted.

The Federal Highway Administration predicts 40 percent of the nation's major highways will be congested by 2035 without major fixes.

"Our highways are clogged with traffic. Our skies are the most congested in the world. This is inexcusable," President Barack Obama told Congress in a speech last week in which he demanded passage of a jobs bill.

"Building a world-class transportation system is part of what made us an economic superpower. And now we're going to sit back and watch China build newer airports and faster railroads? At a time when millions of unemployed construction workers could build them right here in America?"

Despite the sense of urgency, federal highway and transit programs that underwrite about 40 percent of transportation construction have been in a kind of legislative limbo for two years, limping along under a series of short-term extensions because Congress can't figure out how to pay for them.

Republicans want the programs to be funded almost entirely through existing transportation taxes, primarily the 18.4 cents per gallon federal gas tax and 24.4 cents per gallon federal diesel tax. But revenue from the taxes is declining as people drive less and buy more fuel-efficient cars.

GOP Rep. John Mica of Florida, chairman of the House Transportation and Infrastructure Committee, has proposed a six-year, $230 billion plan that would slash annual transportation spending by about 30 percent.

Democratic Sen. Barbara Boxer of California, who heads the Senate Environment and Public Works Committee, has developed a plan that would last only two years and cost $109 billion. But it would maintain current spending levels with some adjustment for inflation.

Federal inaction is "a big variable, right now," Maryland Gov. Martin O'Malley, chairman of the Democratic Governors Association, said recently. "You wouldn't have thought so because it's been routinely extended in the past, but some of these guys in Congress really do believe that bridges are like trees and if you leave them alone long enough they grow taller and stronger with age, so it's hard to say."