D+ Hazardous Waste D D Inland Waterways B D- Levees -- D- Rail -- C- Roads C+ D- School Buildings D D Solid Waste C- C+ Transit C- D Wastewater Cc D- Overall USA Infrastructure G.P.A. Cc D Cost to Improve -- $2.2T Note: The first infrastructure grades were given by the National Council on Public Works Improvements in its rep