Petition the President, as Command-in-Chief of the military, to have the Army Corp of Engineers inspect bridges currently used by the military, for transport of any kind. A report listing all defective bridges would be given to the White House. The President could deem these structures unfit for military uses, then direct the DOD to hire contractors to rebuild them.
As the Interstate Highway System was also conceived and constructed as “Defense Highways”, it could be argued that its condition is vital to our national defense and in the presence of Congressional neglect, indifference, or inaction, the President would have the right to unilaterally approve and pay for [out of DOD slush fund] its maintenance. Bypasses congressional obstruction, create jobs, and rebuilds infrastructure.