State expert details costs, challenges of maintaining Maryland’s aging bridges

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Maryland’s highway bridge infrastructure is aging and the cost of repairing or replacing bridges is increasing dramatically, according to the State Highway Administration’s top bridge expert.

Many structures in Maryland’s bridge inventory were built in the 1950s and are in the later stages of the average bridge’s 80-year life expectancy, Earle S. Freedman, director of the SHA’s Office of Bridge Development, told members of the Greater Baltimore Committee’s Built Environment Committee during its May 28 meeting.

Increasing funding for Maryland’s transportation infrastructure is a top strategic priority of the GBC, which views transportation funding as one of the state’s key economic development challenges.

Funding allocated for repair and replacement of SHA-maintained bridges has increased 79 percent over the last four years – from $39 million in FY 2004 to $70 million in FY 2008, according to state data. Basic costs for bridge construction are escalating. “Where we used to spend $120 per square foot for a bridge, we might be spending $200 (per square foot) now,” Freedman told GBC members.

Nevertheless, the State Highway Administration is holding its own when it comes to identifying and addressing bridges in need of repair, he said. Currently, 129 bridges in the state highway system are classified as structurally deficient – a decrease from 156 bridges in 2001, Freedman reported.

A “structurally deficient” designation does not mean that a bridge is unsafe. Specifically, a bridge is classified as structurally deficient if any one of its three major structural components – substructure, superstructure, or deck – receives an inspection score of 4 or less on a scale of 0 to 9.

The inspection scoring serves as an “early warning sign” to help prioritize allocation of bridge repair and replacement funding. A bridge with a score or 4 on one or more of its components “can carry traffic, but it has come to a point in its life where things should be done,” Freedman said.

Each of the more than 2,500 bridges in the state’s highway system is inspected every two years by one of the SHA’s seven full-time bridge inspection teams. Each April, every state must submit an annual report on the status of its bridges to the Federal Highway Administration.

This year, the SHA will replace or repair 32 bridges, but the next round of inspections will likely identify almost as many additional bridges that have reached the “structurally deficient” stage, Freedman said.

Maryland’s 129 bridges currently classified as structurally deficient comprise 5 percent of SHA-maintained bridges, Freedman reported. However, 256 bridges maintained by local jurisdictions in the state are also classified as structurally deficient – almost twice as many as state-maintained bridges. This represents 11 percent of locally-maintained bridges in the state, according to SHA data. “This is an area where we think the counties could do some work,” said Freedman.

The number of structurally deficient county-maintained bridges has declined from as many as 292 during the last 10 years. In recent years, however, a number of local jurisdictions have not used their full allocations of federal funding for bridge repair that the state passes through to them, said Freedman.

The state is in the process of surveying counties to determine the reasons why they are not using all of the bridge repair funding available to them, said Freedman. One possible reason could be a lack of funds for the 20 percent local match that the federal bridge repair funding requires, he added.

As for the prospect that Maryland could suffer a bridge collapse similar to the I-35 tragedy last August in Minneapolis, Freedman notes that Maryland’s very thorough bridge inspection program is identifying bridges in need of structural repair well before they can become a safety hazard.

The SHA bridge inspection teams regularly examine every element of a bridge down to pipes with diameters as narrow as three inches. Also, as a matter of policy, most bridges constructed by the SHA incorporate structural “redundancy” where failure of a major bridge element will not compromise the bridge’s safety, Freedman said.

“In Maryland, we’re doing a lot more than what is demanded of us,” he said. “But we know we’re doing what is the right thing to do.”

April 2008 State Highway Administration’s report to the Federal Highway Administration on structurally deficient bridges
Earle S. Freedman’s powerpoint presentation to the GBC Built Environment Committee.

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