Crowded schools, traffic-choked roads and transit cutbacks are eroding the quality of American life, according to an analysis by civil engineers that gave the nation's infrastructure an overall grade of D.

A report by the American Society of Civil Engineers (search) released Wednesday assessed the four-year trend in the condition of 12 categories of infrastructure, including roadways, bridges, drinking water systems, public parks, railroads and the power grid.

The overall grade slipped from the D-plus given to the infrastructure in 2001 and 2003.

"Americans are spending more time stuck in traffic and less time at home with their families," William Henry, the group's president, said in a statement.

The report said $1.6 trillion should be spent over the next five years to alleviate potential problems with the nation's infrastructure. Transportation alone requires $94 billion in annual spending, the report said.

The House is to begin debate Wednesday on a six-year, $284 billion highway and mass transit bill, which stalled last year in a money dispute between the White House (search) and Congress.

The report concluded that airports will face the challenge of accommodating more regional jets and super-jumbo jets. Grade: D-plus.

It's uncertain, the report said, whether schools can handle growing enrollment and smaller class sizes required by the No Child Left Behind Act (search). Grade: D.

The report also noted that many transit systems are borrowing money to maintain operations as they're raising fees and cutting back service. Grade: D-plus.