One Cambridge-bound lane of the BU Bridge was abruptly shut down last night after engineering consultants found troubling deterioration of steel beams below the bridge and the sidewalk, which officials decided could not wait for renovations scheduled later this year.
The closure is occurring at an inopportune time for the bridge's namesake: Boston University's commencement is scheduled for tomorrow afternoon at Nickerson Field and is expected to draw 6,000 graduates and 20,000 guests. Colin Reilly, BU spokesman, said, however, that the university is not anticipating problems because convocations are spaced throughout the weekend and the university already encourages people to get to campus on foot or by public transportation.
At least one major walkathon is expected to send 2,000 people across the BU Bridge this weekend, said Wendy Fox, a spokeswoman for the state Department of Conservation and Recreation. Organizers of Avon Walk for Breast Cancer Boston said they were confident participants would be safe and would have enough room on the bridge. Fox said walkers can use the closed lane, but not the sidewalk.
The decision to close the lane was made a day after engineering consultants with TranSystems Corp. notified the Massachusetts Highway Department that its routine inspection of the bridge found "areas of concern" that warranted immediate repairs.
The consultants found two locations of severely deteriorated steel beams - one below the right Cambridge-bound lane and the other on the sidewalk beside it.
The sidewalk on the opposite side of the bridge, where traffic moves from Cambridge to Boston, has already been closed for months as crews conduct interim repairs on that walkway.
The repairs are expected to take three weeks and cost about $100,000, said Fox.
