http://www.brookings.edu/research/opinions/2015/03/10-spending-crumbling-infrastructure-wessel

Infrastructure spending, highways in particular, used to be popular with both Republicans and Democrats in Congress. But, as the flap over the Highway Trust Fund and the gasoline tax indicate, any infrastructure spending bill is trapped by partisan gridlock and distrust. That accounts for at least some of the increasing appetite at the state and local levels for public-private partnerships.