Afternoon traffic on the Capital Beltway near West University Boulevard on April 4 in Silver Spring. (Mark Gail/THE WASHINGTON POST)

Maryland’s top transportation priority should be a $5.8 billion project to widen the Capital Beltway from the Woodrow Wilson Bridge to the American Legion Bridge, a leading national transportation group said Wednesday.

The first step would be the investment of $800 million to relieve the weekday congestion between Interstate 270 and the American Legion Bridge by widening the roadway, adding high-occupancy toll (HOT) lanes and designating lanes in which the direction of traffic could be reversed to accommodate the morning and evening rushes.

The Beltway recommendations topped the list of 40 Maryland transportation projects prioritized by TRIP, a national nonprofit transportation study group supported by insurance companies, unions, equipment manufacturers, and firms engaged in highway and transit construction.

In a report released Wednesday, TRIP (or The Road Information Program) says Maryland’s recovery from the recession and its future economic viability depend on investment in relieving congestion and improving mobility.

Maryland’s transportation system has significant deficiencies that could prevent the state from reaching its full economic potential,” the report says. “Maryland’s economy and quality of life could be adversely affected if its transportation system cannot provide for the efficient movement of goods and people.”

The cost of the top 10 projects TRIP listed amount to almost $13.7 billion.

“We need a billion dollars a year in new revenue to fund the transportation needs of Maryland,” said AAA Mid-Atlantic spokesman Lon Anderson, who participated in the release of the report.

In addition to the Capital Beltway improvements, the projects include replacing the Gov. Harry W. Nice Bridge between Charles County and Virginia ($885 million); widening the Baltimore Beltway ($1.2 billion); building the Purple Line light-rail line between Bethesda and New Carrollton ($1.9 billion); widening and adding interchanges on Route 5 in Prince George’s County ($1.1 billion); widening Route 295 to six lanes near Baltimore ($220 million); building Baltimore’s Red Line light-rail line between Woodlawn and Bayview Medical Center ($2.2 billion); widening U.S. 29 northbound in the Columbia area to three lanes ($104 million); building an interchange at Route 97 and Route 28 in Montgomery County ($142 million); and building an interchange at Route 210 and Kerby Hill and Livingston roads in Prince George’s.

“These are significant projects and, certainly, they are expensive projects,” said Frank Moretti, TRIP’s director of policy and research. “This is a report that’s not fiscally contrained. It’s really to help the public understand that these are the most significant projects that are needed in the state.”

Maryland Gov. Martin O’Malley (D) has proposed a 6 percent sales tax on gas to generate more money for road and transit projects, but high fuel prices have made passage of the package unlikely.

Moretti pointed to Virginia’s use of public-private partnerships to fund transportation projects as a possible model for Maryland.

“Certainly, that’s not going to be appropriate in all of these projects, but it’s part of the funding menu that Maryland has to look at to fund transportation improvements,” he said.

The Nice Bridge is substandard and doesn’t meet needs at peak hours. The report projected that by 2025, weekday bridge traffic will increase by 45 percent and weekend traffic by 33 percent.

The Baltimore Beltway project would require rehabilitating or replacing three bridges at an estimated cost of $85 million.

The proposed 16-mile Purple Line is estimated to carry 60,000 daily riders by 2030, with 21 station stops. Maryland transit planners are seeking federal funding for half of the construction costs and have said it would open in 2020 at the earliest.

“If you look at the Purple Line, and really all of these projects, the Washington area is now rated as the most congested urban area in the country,” Moretti said. “So, the challenge becomes: How do you start to provide the kind of mobility in the region that’s going to reduce those consequences? ”

Widening Route 5 would relieve east-west congestion in Prince George’s and encourage development along the corridor.

Widening three miles of Route 295 from Route 100 to I-195 would ease access to Baltimore-Washington International Thurgood Marshall Airport.

The Red Line is projected to serve 57,000 Baltimore area riders a day in 2030, provide faster, more reliable transit in congested corridors and provide a connection to other transit services.

The widening of Route 29 northbound from Seneca Drive to Route 175 would relieve commuter congestion through Columbia, between Washington and Baltimore. The southbound section already is three lanes.

Construction of the Route 97 interchange would relieve congestion and provide bicycle and pedestrian facilities. It also would speed access to and from the Intercounty Connector and the I-95 and I-270 corridors.

The interchange construction for Route 210 would improve north-to-south movement in southern Prince George’s.

TRIP said it prioritized the state’s transportation needs by evaluating transportation and economic trends, and using data compiled by the Maryland Department of Transportation, the U.S. Department of Transportation, the Federal Highway Administration, the U.S. Bureau of Transportation Statistics and the U.S. Census Bureau.