SHA says it will be for rehabilitation work. 
Dickerson, Md (KM) The Route 28 bridge over the Monocacy River will be closed each weekend through September except during holidays. The Maryland State Highway Administration says crews will be doing rehabilitation work on the span.
The hours of the closure will be from 10:00 PM on Friday to 5:00 AM on Monday.
There will be single-lane closures with a flagging operation Monday through Friday from 8:00 AM until 4:00 PM. .
By Kevin McManus