Public works

Filling them is a short-term fix.

They're tax-free, high-interest and in demand, potentially reflecting confidence in the economy.

The promise of investment in "cutting-edge" technology came out of this year's State of the Union.

With private money at a record level and projects ready to go, the president decides the partnerships are "more trouble than they're worth," leaving states to make their own deals with investors and to hope for federal funding.

Rural America, which supported Trump in the election, could be left out of water and road building investment as states and the president leverage private investment. Trump's plan offers little detail on federal spending and timing. Adding to the uncertainty, a presidential adviser has indicated that states should help themselves.

The smart cans are meant to save time and money, but some trash collectors are skeptical.

Mass unemployment during the Great Depression led to hundreds of thousands of infrastructure projects all over America.