By the turn of the new century, it was obvious that America's transportation system was in deep trouble. Not only had roads, bridges, ports and transit systems fallen into shameful disrepair, but revenue streams were depleted and the system itself was not lined up to meet the new challenges of global competition, energy conservation and climate change. Worse yet, there was no solution in sight.

Then, in 2009, came a brief moment — a flicker, really — when it was possible to imagine a coming-to-grips with the problem.

Why couldn't the nation climb out of its deep recession with a massive rebuilding of its crumbling infrastructure? Millions could be put back to work and, in the end, the economy could recover and the nation could be left with a shiny new and competitive transport system.

And why couldn't the nation, fearful of terrorists and entangled in costly Middle Eastern wars, seize the moment by weaning itself off foreign oil? By raising fuel-efficiency standards and encouraging alternative-fuel cars, mass transit and denser land-use patterns, Americans could make themselves "energy independent" while modernizing transportation and improving the environment.

A new Democratic president, whose party held both houses of Congress, seemed poised to choose that very path. And Minnesota, with veteran congressman Jim Oberstar heading the House Transportation Committee, expected to have a front-row seat, and probably a leg up.

But the moment passed.

President Obama chose health care instead. The Democrats lost the House in 2010 (the recently deceased Oberstar going down with the ship). Obama inserted a burst of transportation projects in his too-small stimulus package and launched some innovative grant programs, but those efforts made barely a dent. Another of his ideas, a public/private infrastructure bank, was quickly shot down.

Republicans, meanwhile, proclaimed themselves nonbelievers in climate change. And the oil companies, as if by magic, began pumping vast supplies of domestic crude, nearly enough to transform the United States into an oil exporter while keeping American drivers hooked on dirty fossil fuels.

"We are still deeply disappointed that that moment came and went," said David Goldberg, spokesman for Transportation for America, a Washington advocacy group.

The upshot: Little progress on a transportation problem that continues to worsen while drawing almost no attention.

Blaming Republicans would be easy, but Democrats failed to pull the trigger when a solution was in their sights. Now, five years later, they're unable even to articulate a comprehensive way forward.

The Minnesota story runs parallel. With control of the governorship and both legislative houses, the Democrats decided to leave transportation on the back burner again this year, gambling that they'll still hold majorities next session. And, in an embarrassing sideshow, infighting among Democrats has raised the cost of — and soon may kill — a light-rail line, something Republicans have never accomplished.

As a vital link in the transit system, the Southwest extension of the Green Line should be built without delay. But the $1.68 billion project also demonstrates the foolishness of the state's present course. Minnesota has ignored the basic axiom of construction: Time is money.

Had the Legislature six years ago provided a sufficient revenue stream and embarked on a systematic, predictable transportation program, the Central and Southwest segments would be completed by now at a savings of hundreds of millions of dollars. Indeed, a 2013 Itasca Project report found that accelerating the metro's transit build-out by seven years would double the private return on a $5.3 billion public investment to as much as $20 billion.

A systematic approach on roads would have paid off in similar ways. But Congress and Obama refused once again to raise the federal gasoline tax, a tax that has not been raised since 1991, leaving the nation's primary source for road-building, the Highway Trust Fund, flat broke by the end of this summer.

For its part, Minnesota acted in 2008 to ratchet up its gas tax by 8.5 cents. But that was its only hike in a quarter-century and not nearly enough to deliver the roads and repairs that the state needs. Indeed, to keep roads at their current poor condition over the next 20 years would require raising the gasoline tax by another 14 cents per gallon — or by 34 cents if we want decent roads. That's how far behind we are.

Negligence seems too tame a word to describe the behavior of elected leaders over the last two decades. They should be calling news conferences and launching investigations on their own backlogs. "The longer we wait, the more expensive it gets," said Margaret Donahoe, director of the Minnesota Transportation Alliance.

By 2020, the nation will be $1.6 trillion behind on infrastructure investment (transport and waterworks), according to the American Society of Civil Engineers. In Minnesota, a governor's study commission concluded that the state must spend an extra $20 billion on transportation over the next 20 years just to stay even — or an additional $50 billion if it wants to be competitive.

"The transportation system hasn't just run out of money; it has run out of logic," said Jim Erkel, transportation director at the Minnesota Center for Environmental Advocacy. What Erkel means is that neither the funding model nor the system itself meets the needs of a changing marketplace. People want cleaner, more efficient transportation, and some want choices beyond cars and long commutes. That means more transit and more streets designed for biking and walking. "If we just patched up the old interstate system, it wouldn't fit the new reality," Erkel said.

Obsolete funding streams must also be fixed. The value of the per-gallon gasoline tax, the main ingredient in the complex stream of revenues that support road-building, has been severely eroded by fuel-efficient engines, fewer miles driven and anti-tax fervor. A new tax, based on vehicle weight and distance traveled, is the right answer if privacy concerns can be overcome. In the meantime, imposing a sales tax on fuel to pay for roads and bringing the metro sales tax for transit up to a level charged by comparable cities will be required. There's no other way.

Awarding priority to projects with the best return on investment would help, too. Contrary to professed belief among rural legislators, it's the metro area that gets shortchanged on road money. Figures from the nonpartisan House Research Department show that metro counties contribute $134.4 million more in taxes than they get back in road projects.

"Value capture" is another intriguing idea. Had the interstate system captured even a tiny slice of the enormous real-estate value it generated (fast food, shopping malls, etc.), there would be no infrastructure crisis.

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For most Minnesotans, of course, it seems hardly a crisis at all. As long as gas is cheap and potholes are patched, it's hard to see the problem. But beneath all the patching and layering, roadways and bridges, many of them built in the 1950s and '60s, are coming to the end of their life spans. More patching won't do. Neither will ignoring the evidence that quality roads and transit draw investment — and that investment brings jobs and prosperity. A recent survey by the Urban Land Institute found that "quality infrastructure" outranked "market demand" as the top factor in private investment decisions.

Voters need their elected leaders to tell them these things. Specifically, they need Democrats to tell them. (Republicans won't be helping on this, because taxes are involved.) Just reading polls and shrugging shoulders isn't good enough. That's not leadership.

Gov. Mark Dayton and the DFL caucuses are doing Minnesota no favor by again pushing this issue into the cloudy future.

Steve Berg writes about urban design and transportation.