The American Society of Civil Engineers, which released its 2017 "Infrastructure report card", has given the nation's overall infrastructure a grade of D+.

The D rating is considered “poor” and “at risk,” just one step above failing and unfit for purpose.

The association said it evaluated 16 categories of infrastructure, ranging from rail to schools to airports to dams. Its committee consists of civil engineers from across the country who assessed categories such as capacity, condition, funding and public safety, to assign grades across the 16 segments.

While the overall grade was unchanged from 2013, there were some improvements: hazardous waste management, inland waterways and locks, levees, ports, rail, schools and wastewater treatment, according to the report. Grades fell for parks, solid waste management and transit. They stayed the same for aviation, bridges, dams, drinking water, energy and roads.

In addition to assigning grades to America's ports and parks, the 2017 report card projected a total investment of $4.59 trillion that would be required to bring U.S. infrastructure from where it stands today — at a D+ — to a B grade.

"We need our elected leaders ... to follow through on those promises with investment and innovative solutions that will ensure our infrastructure is built for the future," said ASCE President Norma Jean Mattei, in a statement.

2017 ASCE Infrastructure Report Card

2017 Overall GPA: D+

  1. Aviation D
  2. Bridges C+
  3. Dams C+
  4. Drinking Water D
  5. Energy C+
  6. Hazardous Waste D+
  7. Inland Waterways D-
  8. Levees D
  9. Ports C+
  10. Public Parks/Recreation D+
  11. Rail B
  12. Roads D
  13. Schools D+
  14. Solid Waste C+
  15. Transit D-
  16. Wastewater D+