The East Deer Park Bridge spanning over the CSX railroad tracks between Gaithersburg and Washington Grove closed Wednesday for a 10-week, $450,000 dollar project to replace its aging timber bents supports.
The 63-year-old, one-lane bridge, also known as "Humpback Bridge," handles traffic on East Deer Park Drive to and from Railroad Street. East Deer Park Drive will be closed between Central Avenue and Railroad Street. The detour route takes motorists down Central Avenue to Oakmont Avenue then to Railroad Street.
Trains will not be disrupted, according to a statement from Montgomery County. The bridge is expected to reopen Aug. 30.
Because the bridge is listed on Montgomery's historical atlas, the county's Historic Preservation Commission had to approve the repair project as not constituting a "substantial change." Transportation officials had for years wanted to raze and replace it with a two-lane structure, but neighbors and preservationists opposed the idea.
The asphalt roadway is supported by a timber bridge deck that rests on steel beams. Concrete abutments and timber bents support those beams.
A November study by the U.S. Forest Products Laboratory found that the timber bents "were in an advanced state of decay and must be replaced as soon as possible, preferably within [12] months," according to a county statement.
The deck, steel beams and concrete abutments are in "satisfactory condition," according to the county.