If the U.S. Interstate Highway system is to continue to provide reliable and safe transportation for Americans, a major long-term funding commitment will be required, according to a new report by the transportation research group TRIP.

It has been nearly 60 years since President Eisenhower signed the Federal-Aid Highway Act, which led to an expansion of the U.S. road system, bringing the nation’s Interstate Highway System into existence.

As roads age and become increasingly congested, they are in need of modernizing, and TRIP is urging the government to consider a more significant, long-term funding plan to bring the road system into the 21st century.

“The interstate highways gave the United States incredible gains in mobility of personal travel and cargo shipments as new segments opened in state after state,” said Bud Wright, executive director of the American Association of State Highway and Transportation Officials. "However, we must face the facts of where we are today.”

Highway congestion is increasing every year. Today, more than two out of every five miles of highway are congested, according to TRIP.

The recently signed FAST Act will provide $305 billion in funding over the next five years, boosting highway funding by 15% over previous levels. The commitment may only be a step in the right direction, according to TRIP, which says that the funding falls far short of the level needed to improve conditions and meet the nation’s mobility needs.

The current backlog of needed improvements for the Interstate Highway system is estimated to be $189 billion, according to the Department of Transportation. The backlog includes $59 billion to improve pavement conditions, $30 billion to improve bridges and $100 billion for system expansion and enhancement.

Current annual spending levels are estimated to be around $20 billion, but the U.S. DOT estimates that $33 billion is needed annually to complete repairs and improvements needed to maintain the system and relieve traffic congestion.

“State departments of transportation are struggling to maintain their portions of this critical national network while demand keeps growing, even when many states have substantially increased their highway funding,” said Wright. "As a nation, we must ask ourselves if we are taking care of that asset and increasing its value and the economic payoff it delivers, or if we are letting it languish and lose value."

To read TRIP's full report and recommendations, click here.