The U.S. National Park Service and U.S. Federal Highway Administration closed lanes on the iconic Arlington Memorial Bridge, which spans the Potomac River in Washington, D.C., following a May 15 bridge inspection.

Doug Hecox, FHWA spokesman, said inspectors found that previously identified deterioration on load-bearing support beams on the 83-year-old drawbridge span were "more advanced than anticipated." The park service closed sidewalks and outer lanes on both sides of the span. Pending repairs, which now are out to bid, officials imposed a 10-ton limit and banned large vehicles, including busses.

About 68,000 vehicles cross the bridge on a typical workday. The repair project is expected to begin in July and last six to nine months.