WASHINGTON — President Obama’s proposed budget envisions a nearly half-trillion-dollar transportation construction spree that would seek to upgrade the nation’s roads, bridges and ports by imposing new taxes on overseas earnings by American companies.

The six-year, $478 billion infrastructure plan would provide a 33 percent increase in funding for big, new public works projects. The nation’s transportation trust fund is set to run out of money this summer, but if this program is passed by Congress it will increase funding for transit by 75 percent and finance construction jobs across the country.

“Democrats and Republicans used to agree on this,” Mr. Obama said in his State of the Union address last month. “So let’s set our sights higher than a single oil pipeline. Let’s pass a bipartisan infrastructure plan that could create more than 30 times as many jobs per year, and make this country stronger for decades to come.”