A total of 410 of Maryland?s bridges have deteriorated to the point where they are structurally deficient, according to the U.S. Department of Transportation.
Most are located in Washington, Prince George?s and Frederick counties. And the Chesapeake Bay Bridge is among 10 in Maryland slated for inspection — each is similar in design to the I-35W Bridge in Minnesota that collapsed Wednesday.
Yet Maryland state highway and transportation officials insist the bridges are safe.
“Structurally deficient doesn?t immediately imply that the bridges are unsafe or likely to collapse,” said State Highway Administration spokesperson Kelli Boulware.
She said bridges are rated on a scale o 0-9, with nine meaning excellent and zero indicating a bridge needs to be closed to traffic and pedestrians.
Newly installed bridges or those that have been replaced normally get the highest rating.
In determining deficiencies, Boulware said inspectors consider the bridge deck — the main riding surface, the superstructure — beams and girders and the support that holds up a bridge.
“Inspectors look to see if there are things like potholes in riding surface or if some structural preventive maintenance needs to take place,” she said.
SHA spokesperson David Buck, added, “They look for cracks in the concrete, rusting, everything. We do thisall the time. This didn?t just get started yesterday.”
He said any rating of five and below is designated structural deficient. “Then [the project] becomes eligible for federal funding.”
Maryland spends $95 million annually on bridge maintenance and repair on 2,800 of 5,200 bridges. Fourteen hundred — including the Bay Bridge — are more than 50 years old.
Of the 130 structurally deficient bridges the state is responsible for, 24 are under construction and the remaining 106 are in some stage of preliminary engineering, according to the SHA. The other 280 bridges are the responsibility of counties.
“A [functionally obsolete] bridge may not be wide enough to accommodate day-to-day traffic, or it may have height restrictions,” Boulware said.
“Some bridges [such as those built between the 1940s and ?70s] were designed to carry only a certain amount of traffic,” she said.
“However, with today?s increased traffic volumes many of them are no longer functional.”
LOCAL INSPECTIONS
State officials plan to inspect these 10 bridges that have a similar design to one that collapsed in Minnesota.
-The Chesapeake Bay Bridge. The east and west spans of the bridge count will be inspected.
-Thomas J. Hatem Memorial Bridge, which crossed the Susquehanna River on U.S. 40 between Havre de Grace and Perryville in northeast Maryland.
-Millard E. Tydings Memorial Bridge on I-95 over the Susquehanna River at Havre de Grace.
-U.S. 522 over the Potomac River in Washington County.
-U.S. 340 over the Potomac in Washington County.
-MD 144 over the Monocacy River in Frederick County.
-U.S. 40 over Licking Creek in Washington County.
-I-495 over Northwest Branch in Montgomery County.
-MD 32 over the Monacacy in Carroll County.
-Associated Press
