Unsafe conditions have led to an emergency closure of portions of the Arlington Memorial Bridge in Washington, D.C.

Safety concerns for traffic and pedestrians on the Arlington Memorial Bridge within the George Washington Memorial Parkway led to closure Friday of two curbside lanes and four feet of adjoining sidewalks. National Park Service officials said the closures would remain in place until emergency repairs could be completed.

Additionally, a 10-ton weight limit across the entire 2,100-foot bridge was posted, the Park Service said in a release Thursday.

"The load restriction, which will eliminate most bus traffic, will remain in effect indefinitely," the agency release said.

During a routine annual inspection of Arlington Memorial Bridge, Federal Highway Administration engineers identified a corroded area that warranted further evaluation. The follow-up evaluation revealed that secondary load-bearing support beams, located at the bascule span, are corroding at a faster rate than anticipated and no longer meet load-bearing standards. Using the latest structural scanning technology and confirming the results with core samples of the deck, the inspection also revealed significant deterioration of the concrete deck. Instituting the load limit will help extend the life of the deck for passenger vehicles.

'œWith the precautionary measures in place, Arlington Memorial Bridge is safe to travel within the open lanes, sidewalks and posted load limits,' said Alexcy Romero, George Washington Memorial Parkway superintendent. 'œFederal Highway Administration engineers used the latest technology to locate the compromised areas and used an engineering-driven decision process to make their recommendations.'

The National Park Service and Federal Highway Administration are expediting temporary repairs originally scheduled for September 2015 to address the corrosion in the bascule span. The work includes strengthening and repairing portions of the sidewalk throughout the bridge, adding new support beams along portions of the bascule span and resurfacing the roadway with an ultra-thin bonded material. Repair work is expected to begin in July and last 6-9 months.

'œThis two-lane closure of the Arlington Memorial Bridge, which is the second partial shutdown in the last 10 days, is indicative of the disrepair facing our roads and bridges across our country and the National Park System," said Laura Loomis, the deputy vice president of government affairs for the National Parks Conservation Association. "This closure, likely to be long-term, comes at the very time Congress is delaying discussions about future transportation funding, including within our national parks. In the meantime, roads and bridges across the country and within our national parks continue to erode, jeopardizing public safety and increasing the ultimate cost of repair. Unless Congress passes a transportation funding bill that increases resources for national parks, our park'™s roads and bridges will continue to deteriorate."

Since 2012, the National Park Service and Federal Highway Administration have been conducting public outreach and developing a project for comprehensive long-term rehabilitation and repair of Arlington Memorial Bridge, currently estimated to cost approximately $250 million. The purpose of this project is to restore the structural integrity of the bridge while protecting and preserving the memorial and the historic characteristics. 

Arlington Memorial Bridge, listed in the National Register of Historic Places, spans the Potomac River in Washington, D.C. Regarded as Washington'™s most beautiful bridge, Arlington Memorial Bridge is not only an important part of the roadway transportation network, but also a national memorial symbolizing reunification of the North and the South following the Civil War, the Park Service said.

The bridge connects the Lincoln Memorial and Arlington House, the Robert E. Lee Memorial, at Arlington National Cemetery. When it opened in 1932, it was the longest, heaviest, and fastest opening drawbridge in the world, according to the Park Service. The drawbridge was last opened on Feb. 28, 1961.