Transportation Secretary Ray LaHood today said that later this year, the president could make a significant announcement about transportation funding -- but he offered few details on what, exactly, such an announcement might entail.

LaHood's comments came at a gathering of officials from the transportation construction industry in Washington, D.C., Tuesday.

LaHood's comments came in response to a question about adopting a mileage-based user fee to replace the gas tax. "The president's going to be big and bold about what his vision is," Lahood said. "I'm not going to steal his thunder."

LaHood said he expects President Obama to make an announcement about transportation funding later this year, but it probably won't happen until the debates about immigration, gun control and sequestration play out. LaHood will leave office once Charlotte Mayor Anthony Foxx is confirmed as his replacement.

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If the president does take up the issue, it would be significant. Stakeholders in the transportation community have become increasingly vocal in recent years over the disconnect between the president's tendency to use lofty rhetoric about the need to invest in transportation while simultaneously avoiding serious policy proposals on the matter.

Obama's only major attempt at suggesting how to pay for infrastructure -- a so-called "peace dividend" resulting from money saved by winding down wars in Iraq and Afghanistan -- has been derided by many as a gimmick.

Earlier this year in his State of Union speech, Obama touted a plan to create jobs by spending $50 billion on infrastructure in urgent need of upgrades. But when the White House released more details about the plan a few days later, it didn't mention a funding mechanism. Few were surprised.

"The fact of the matter is I think it is a harmful thing, the way they keep putting this proposal out there year after year, because they don't really have a realistic way to finance it," Jack Schenendorf, an attorney who spent 25 years on the staff of the House Transportation and Infrastructure Committee, told Governing earlier this year. "It really turns into a mirage, kind of. I don't think that's helpful."

LaHood was famously rebuked by the administration in 2009 after he said he'd like to consider the idea of charging motorists based on how many miles they drive. But a proposal like that is viewed widely among transportation wonks as the best step to address the unsustainable gas tax, which isn't indexed to inflation, hasn't been raised in 20 years, and stands to become less useful as vehicles become more fuel-efficient.

During reauthorization of the last highway bill, lawmakers failed to find a way to boost revenue for infrastructure -- even though lawmakers of all stripes often emphasize the need to improve roads and bridges. The biggest stumbling block was the political challenge of finding a significant revenue stream to replace or supplement the gas tax.

The administration was not considered to have played a meaningful role during that debate, so if the president did put forward a serious transportation funding proposal, it could help shape that debate when discussions about the highway bill ramp up. The current highway bill expires in September 2014.