INTERACTIVE MAP: Fixing ‘Structurally Deficient' Bridges Will Cost Mass. Billions

Crumbling concrete, exposed rebar, and rusted steel. That’s what pictures from an inspection report obtained through an open records request show on one of the most traveled bridges in the state.  

Known simply as structure #111, a bridge on the Massachusetts turnpike in Allston is the gateway to Boston. 

"That is a structurally deficient bridge that we put a lot of money into every year to keep safe," said Jonathon Gulliver, the state highway administrator for the Massachusetts Department of Transportation.

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Structure #111 is just one of 423 bridges across the state deemed structurally deficient.

”In some cases, it may be considered structurally deficient because you have some structure loss that's causing your load carrying capacity to be degraded, but not to a point where normal traffic will face problems,” said Gulliver. “Structurally deficient does not mean unsafe. Our bridges are all safe.”

Though deemed safe, the state is investing billions of dollars to repair or replace structurally deficient bridges across Massachusetts.

The federal highway administration measures elements of bridge safety on a scale of 0-9…with 9 being excellent. 

Structurally deficient bridges usually have a score of 4 or less in one of three critical structures: the deck, superstructure, and substructure. 

We met Gulliver at the I-90 and 128 interchange in Weston, where the state plans to replace five of the bridges at the interchange and repair three others with an estimated cost of $230 million. 

“This bridge, again, has some elements to it, a little bit of degrading concrete. You obviously have some rust,” said Gulliver, pointing at an onramp that according to state data has a superstructure rating of 4.

Massachusetts just received $3 billion from the new federal infrastructure plan that will help pay for these projects and MassDOT plans to spend an additional $1 billion through its Next Generation Bridge Program. 

For more data on bridges across the state, visit the MassDOT website here.

 "This new program enables us to really address a lot of those smaller bridges, ones that are important," he said.

Many of the state’s worst bridges, like the one that spans the Merrimack river in Haverhill on I-495, are in the process of being replaced. 

A similar fate awaits structure #111, which will eventually be replaced through the Allston Multimodal Project. 

"This is a transformative project for Boston," said Mary Connaughton of the Pioneer Institute. 

Connaughton has been following the Allston Multimodal Project for years. 

According to a recent presentation, there are a number of plans that would bring I-90 back to grade. The current viaduct would be destroyed, opening up more land for the area and potentially paving the way for a new commuter rail station. The estimated cost is more than $1 billion.  

"It's going to change the western city forever. It's going to bring more jobs. It's going to bring more housing," Connaughton said.

But even as its replacement is built, the current bridge, which has both a deck and substructure condition rating of 4, will need to be maintained. 

The state currently spends between $1-3 million annually just to keep the bridge in its current condition, and Gulliver says MassDOT will spend another $75 million just to keep the bridge drivable for the next ten years. 

“That has always been envisioned as phase one of that larger project. So, moving it up now we really think makes a lot of sense, keeps it safe, keeps it reliable," said Gulliver.

MassDOT estimates it will take at least two years to design the project and another 6-10 years to complete construction before the tear down. 

The agency hasn’t settled on a final design just yet. Meanwhile, supply chain issues, inflation, and labor costs could put the project over budget and behind schedule.

"It's going to take time to get the permitting done, get all the bidding out, get the financing in order. This is not going to happen overnight," said Connaughton. "The longer the project takes to get done, you know, the more deterioration there's going to be on the existing viaduct."

MassDOT plans to provide an update on the Allston project soon. The agency is also hoping federal funding will help move things ahead, but the clock is ticking. 

“It's always a race against time on these bridges. We build them to have a 50-to-75-year life span,” said Gulliver.

In the meantime, Gulliver says they’ll make sure structure #111 and all the structurally deficient bridges in Massachusetts remain safe.  

 “Drivers can have confidence that the roadways that they drive on and the bridges that they drive on are safe. We spend a huge amount of effort to ensure that they are,” said Gulliver.