America's recent wave of infrastructure spending is beginning to pay off.
The condition of the nation's roads, bridges, ports, railways and other critical infrastructure got a bit better over the last four years, according to a "report card" released Tuesday by the American Society of Civil Engineers. The trade group rated America's infrastructure a D+, compared to a D in 2009, the last time it was graded.
A D+ is the highest the country has ever scored in the 15 years ASCE has issued its report. It ties the grade America got in 2001.
Still, the report said the country needs to do more. The nation will spend $2 trillion on infrastructure by 2020, but should be spending $3.6 trillion, the group estimates.
"A D+ is simply unacceptable for anyone serious about strengthening our nation's economy," ASCE President Gregory DiLoreto said in a written statement.
The improvements were due to a renewed focus on infrastructure investment from state and local governments, an increase in private investment, and greater federal spending, including some $80 billion allocated for such projects in the 2009 stimulus bill.
Infrastructure investment is something President Barack Obama has pushed since taking office, with mixed success. The stimulus spending was approved, but additional money for further investment has yet to pass Congress.
Areas showing improvements included drinking water, roads, bridges, rail, and the disposal and recycling of solid waste and wastewater.
Rail infrastructure showed the largest improvement, jumping from a C- to a C+, largely thanks to investments from private freight rail companies.
The report said freight haulers pumped $20 billion a year over the last four years into improving rail lines and port facilities -- an amount equivalent to the entire federal stimulus spending on infrastructure.
Amtrak also received several billion dollars under the stimulus effort for track improvements. The passenger rail service saw its busiest year ever in 2012.
The country's bridges, closely watched since a 2007 collapse in Minneapolis killed 13, improved to a grade of C+. Still, the report said one out of every nine bridges remains "structurally deficient."
The country received its highest score in the category of solid waste. America's recycling rate is now 34 percent, more than double the rate in 1980.
Areas receiving a near-failing grade included the country's levees and inland water way system, which handles much of the nation's transport of bulk goods like grains, coal and metals.
Schools also received a D. The report noted that "almost half of America's public school buildings were built to educate the Baby Boomers -- a generation that is now retiring from the workforce."