President Obama told reporters today that he’s committed to a six-year plan to rebuild 150,000 miles of roads, lay and maintain 4,000 miles of railways, restore 150 miles of runways, and create a national infrastructure bank.

He made his remarks after meeting with Transportation Secretary Ray LaHood, former Secretaries Samuel Skinner and Norman Mineta, L.A. Mayor Antonio Villaraigosa, Pennsylvania Governor Ed Rendell, and Treasury Secretary Tim Geithner. They all stood beside him as he spoke to the press.

The president’s remarks echo the promises he made on Labor Day, when he announced a $50 billion “down payment” on transportation and infrastructure spending. LaHood later told activists that the administration planned to get behind a six-year plan in February.

President Obama held up a report, released last week, from a conference chaired by Secretaries Skinner and Mineta, in which they laid out the dismal state of infrastructure in this country and the need for more funding. Obama said choosing whether or not to invest in infrastructure was “a choice between decline and prosperity.”

He also referred to a new report by the Department of the Treasury with the Council of Economic Advisers on the economic impact of infrastructure investment [PDF], emphasizing the significant return from projects that are rigorously analyzed and selected “rationally.” Noting that the average American family spends one-third more on transportation than on food, the report bolsters the administration’s strategy of investing in projects that give middle-class Americans options besides driving.

Obama’s comments — and those of the Democrats and Republicans who flanked him — underlined the traditional bipartisan support for infrastructure spending. With the elections looming, there hasn’t been bipartisan support for anything in Washington lately. They’re hoping that will change.

Perhaps as a hedge against Republican attacks, Obama emphasized that “it should not take another collapsing bridge or failing levee to shock us into action. So we’re already paying for our failure to act.”

With that one line, evoking the needless deaths in New Orleans and Minneapolis, he practically dared Republicans to oppose this plan on the basis that it involves too much spending.

The administration’s long-awaited transportation push is finally underway. We’ll have more analysis in the days ahead.