The nation’s highway and transit systems need to overcome a nearly trillion-dollar investment backlog, according to a new report on the state of America’s transportation infrastructure commissioned by the Department of Transportation.

The report, 2015 Status of the Nation’s Highways, Bridges and Transit: Conditions and Performance, identified an $836-billion backlog of unmet capital investment needs for highways and bridges.

Conditions and Performance is a biennial report to Congress that provides information on the physical and operating characteristics of the highway, bridge and transit components of the nation's surface transportation system.

“We have an infrastructure system that is fundamental to the nation’s economic health, and it needs greater attention and resources,” said Secretary of Transportation Anthony Foxx. “Improving our nation’s roads, bridges, and transit helps create jobs, connects communities and ensures that our nation is equipped for the future.”

Addressing the growing backlog while still meeting other needs over the next two decades will require $142.5 billion in combined transportation spending from state, federal and local governments.

In 2012, the most recent year for which the report’s data was available, federal, state and local governments combined spent $105.2 billion on infrastructure– 35.5% less than what was needed to improve highways and bridges.

“The case for more investment in our nation’s transportation system is clear,” said Federal Highway Administrator Gregory Nadeau. “A strong transportation system will make businesses more productive and freight shippers safer and more efficient while improving America’s quality of life.”

The report also indicates a $26.4-billion need per year to improve the condition of transit rail and bus systems. In 2012, total spending to preserve and expand transit systems was $17 billion. The report indicates that if spending were to remain at the $17-billion level, overall transit system conditions are expected to decline over the next 20 years. This would increase the transit system preservation backlog to $122 billion, up from $89.8 billion.

Other findings in the report include a decrease in structurally deficient bridges from 14.2% to 11% in the decade between 2002 and 2012.

Road quality also improved with 44.9% of travel taking place on smooth pavement, up from 43.8%. Light rail has grown faster than any other transit mode, but not fast enough apparently as traffic delays were up to 41 hours per year for the average commuter – an increase of 2 hours.

“The results of that neglect can be seen throughout our country as both reliability and safety suffer,” said Carolyn Flowers, acting Federal Transit Administrator. “We must increase investment in public transportation nationwide, because we must take immediate action to bring our transit infrastructure into a state of good repair and provide the world-class service that Americans deserve.”