The American Society of Civil Engineers says infrastructure across the United States has improved slightly, but is still below average and may soon fail to meet society's needs.
The ASCE issues a report every four years to show the state of the nation's roads, bridges, drinking water systems, mass transit systems, schools, and systems for delivering energy. The society says U.S. infrastructure went from a "D" grade in 2009 to a slightly better, but below adequate, "D+" grade in 2013.
The grades given to each infrastructure system range from an "A+" for exceptionally good condition, to an "F" for failing condition.
Tuesday's report is the first time since 1998 that the grades rose overall and in several sectors.
The ASCE estimates that raising the infrastructure grade to a "B," defined as "adequate for now," would require $3.6 trillion in investment by 2020. That is $1.6 trillion more than what is now set aside for infrastructure repair.
ASCE President Gregory DiLoreto says the United States needs to be "proactive" in taking care of its infrastructure to assure that it will be there for generations to come.