About 800,000 vehicles per day travel over several bridges south of Boston that are federally classified as “structurally deficient,” or in need of significant repairs, maintenance, or replacement, according to a report released this month.
The report, compiled by national advocacy group Transportation for America, found that Massachusetts has the 28th-highest percentage of structurally deficient bridges, with just under 10 percent of its 5,132 bridges given that ranking.
Of the state’s structurally deficient bridges, averaging 76 years of age, about 30 are located in communities south of Boston, according to the report and state transportation data.
The designation doesn’t necessarily mean that the bridges are unsafe or in danger of collapse, but rather show they are past the average 50-year lifespan for bridges. Among the oldest structurally deficient bridges in this area is a 138-year-old span on Washington Street that goes over the Neponset River in Walpole, which carries an average of 17,500 cars a day.
“It’s modernization that’s needed here; replacing those bridges with something that’s more functional,” said Jim Hadfield, transportation planning manager for the Southeastern Regional Planning and Economic Development District in Taunton. “Most bridges were built so many years ago [that] today they’re not up to the standards of traffic flow, weight of traffic, and the volume of traffic.”
Some bridges, like Duxbury’s Powder Point Bridge, are listed on the state’s structurally deficient list, but federally categorized as “functionally obsolete,” a lower-priority designation that means the bridge isn’t built to today’s standards, such as being able to handle present-day traffic volume. Although not necessarily a safety indicator, it was the same designation assigned to the Interstate 5 bridge in northern Washington that collapsed over the Skagit River last month.
Despite having the oldest bridge stock in the continental United States, Massachusetts is doing better than many other states in its efforts to reduce the number of structurally deficient bridges, according to the report, which used data from the National Bridge Inventory.
Since launching the $3 billion, eight-year Accelerated Bridge Program in 2008, state transportation officials have reduced the number of structurally deficient bridges to 466 from 543 as of April, said Frank DePaola, highway administrator for the state Department of Transportation. The program, funded with federal and state transportation bonds, was launched after the 2007 collapse of the structurally deficient I-35W Mississippi River Bridge that killed 13 people.
“We were number 28, but the trend is that we were improving, not degrading,” DePaola said. “We’re going in the right direction.”
The accelerated repair program targeted several bridges in communities south of Boston, including the Fore River Bridge in Quincy, which is on a 24-hour construction schedule through at least this week, as project managers push to stick to the timetable to replace the current temporary structure. At an estimated $245 million, the Fore River Bridge replacement is among the most expensive projects on the state’s list, just behind the $255 million Longfellow Bridge project in Cambridge.
Of the hundreds of bridge projects in various stages of activity on the state Department of Transportation list, 18 are in south communities from Quincy to the Wareham-Bourne line.
“From our perspective, the state has done due diligence picking up the worst of the worst coupled by the most heavily traveled [bridges],” said Chris Walker, spokesman for Quincy Mayor Thomas P. Koch, noting the completion of work on the Neponset River Bridge. “But being on the report doesn’t mean that the bridges are on the verge of collapse. It means there are some issues that need to be addressed and, if allowed to continue to degrade, there could be structural issues.”
Mansfield Town Manager William R. Ross, whose town has three bridges on the state’s structurally deficient list, including a span on West Street over the Wading River, said the bridges are safe but need updating.
“Sometimes structurally deficient also means the lanes for the street are too narrow, or the guardrails aren’t too high, or there’s not pedestrian usage,” Ross said. “Bridges are neglected nationwide; it’s not unique to Massachusetts. We have a tendency to build things and just leave them, and not take care of them, and not make sure they’re replaced under the belief that they will last forever.”
With the average age of the state’s bridges at 57, and the Accelerated Bridge Program scheduled to end in 2016, state legislators should adopt dedicated bridge funding strategies so that those projects don’t have to compete for the same dollars as other transportation needs, like road resurfacing, said David Goldberg, spokesman for Transportation for America in Washington, D.C.
“We have to stay on top of the bridges because if we don’t they’re going to get worse,” Goldberg said. “It is one of those things that as long as things are going fine, we tend to ignore it. There’s a lot of political pressure to build new projects. Ribbon-cuttings are good things, but bridge maintenance is less obvious.”
Katheleen Conti can be reached at firstname.lastname@example.org. Follow her on Twitter @GlobeKConti.