The 117-year-old truss bridge is in poor condition and was long overdue to be replaced. However, the construction will require a series of lane closures that will affect the commutes of the 40,000 cars a day, and it will unfold as several other major construction projects add to traffic disruption in that side of Boston. State officials expect to put the project out to bid by the end of September.

The North Washington Street Bridge, a key artery at the city’s northern end and one of the oldest bridges of its type in the state, will be replaced in stages beginning next spring, with construction expected to take as long as five years.

Another big bridge in Boston is about to get a total makeover.


“This bridge is over 100 years old. It’s structurally deficient and has been kept open by necessity,” said Jonathan Gulliver, acting highway administrator for Massachusetts. “It needs to be replaced. It’s past the point where you can actually rehab it.”

By the time construction begins on North Washington, the state will be weeks into another big job: repairing and repaving a 1,675-foot stretch of the Tobin Bridge. That work is expected to cause lane closures and traffic disruptions into 2020. Meanwhile the Wynn Resorts casino in Everett is also under construction, scheduled to open in 2019. And between the bridge and casino, Sullivan Square and Rutherford Avenue are scheduled to be reconfigured beginning in 2021. Plus, construction on a major property development is also underway near North Station, disrupting traffic on Causeway Street.

A rendering of the proposed update to the North Washington Street Bridge. MassDot

The start of the North Washington bridge project also coincides with the expected completion of the Longfellow Bridge, another century-old crossing over the Charles that has been under reconstruction since 2013. A few miles west, the Commonwealth Avenue bridge over the Massachusetts Turnpike is halfway through a two-stage rebuilding that will resume next summer.


Para Jayasinghe, an engineer for the city of Boston, said the traffic impacts from the Charlestown bridge construction will be somewhat alleviated by roadwork Wynn is undertaking this fall, which is mostly focused on limiting congestion around Sullivan Square.

But residents on either side of the North Washington Street Bridge are already worried about the impact.

“We don’t have supermarkets in the North End,” said Mary McGee, president of the North End/Waterfront Residents’ Association. “A lot of people go to Chelsea for supermarkets. If you can’t get over this bridge easily, it’s almost impossible to get there.”

Meanwhile, Michael Parker, chairman of the Friends of the Charlestown Navy Yard, said some residents fear commuters from northern suburbs who already use Charlestown to bypass Interstate 93 will worsen traffic during construction.

“There should be signs up as far back as Woburn encouraging drivers to get out of their cars and get on the commuter rail,” he said.

Once complete, the bridge will have a number of new features, including cycle tracks and sidewalks to improve what has been an unglamorous trek along the Freedom Trail.

Transit users will also benefit, as a single inbound lane will be reserved exclusively for buses, while two lanes will still be open to regular traffic, as is the current scheme.

These changes are applauded by advocates who have called for less auto-centric approaches to transportation.


“It will be a beautiful, wonderful place to be if you’re not in a car,” said Stacy Thompson, executive director of the Livable Streets Alliance. “And we are really excited about the bus priority.”

The bridge is also going to have a new look, with a design meant to compliment the nearby Zakim Memorial Bridge, replacing the aged truss with tall, white adornments lining the central span like a skeleton.

State officials expect the project to cost between $140 million and $150 million, depending on final bids. Most of the funds will come from the federal government.

The five-year building schedule is necessary because of complexities of building over water, moving utilities, and keeping the passage partially open to vehicles.

The plan is to rebuild the bridge in halves, and keep three lanes open to traffic: two heading into downtown Boston, one outbound to Charlestown. A center bay on the existing bridge that is currently shut off will be used to manage traffic during construction. The southbound side of the bridge will be torn down and replaced first, and then put into service while the second half is demolished and rebuilt.

Adam Vaccaro can be reached at adam.vaccaro@globe.com.