Rebuilt Longfellow Bridge may reopen by June 2018

The Longfellow Bridge is now expected to be fully open to all traffic by June 2018, a few months earlier than last estimated.David L. Ryan/Globe staff/file 2016

The long-delayed Longfellow Bridge is now scheduled to be fully open to all traffic by June 2018, a few months earlier than last estimated, after state transportation officials and contractors agreed to temporarily close one side of the bridge to pedestrians and bikers.

The change will inconvenience pedestrians and bicyclists traversing the crucial link between Cambridge and Boston, but transportation officials say that, after announcing a two-year delay, they were eager to allow full use by all drivers, pedestrians, and cyclists as soon as possible.

“The job’s run behind for a variety of reasons, so we’re working very hard at ways to gain time and establish full, beneficial use at an earlier date,” said John McInerney, a construction engineer for the Massachusetts Department of Transportation.

The previous estimated opening date was September 2018.

State officials have closed pedestrian and cyclist access to the sidewalk next to the westbound traffic lanes, which were closed to cars earlier this summer. Bicyclists riding east into Boston use the eastbound roadway, while cyclists riding westbound into Cambridge will now travel on the sidewalk next to that roadway.

The arrangement will last until June 2018, when the bridge will open to all traffic, McInerney said.

Construction on the 110-year-old span, known for its iconic “salt-and-pepper shaker” towers, began in the summer of 2013 and was scheduled to last three years. But last year officials announced a two-year delay.

The latest reopening estimate follows a Globe report that transportation officials and the contractor don’t have a handle on how much the bridge will ultimately cost.

The project is being completed by a consortium of construction companies, White-Skanska-Consigli. Officials say they don’t expect the costs of delays to exceed the $303 million the state has budgeted for the project, including contingencies and incentives for the contractor that were meant to keep the project on schedule.

Officials have blamed the delays on complications related to rebuilding the bridge with historical accuracy and keeping it open during construction for the MBTA’s Red Line, cars, pedestrians, and bicyclists. Under the original timeline, both sidewalks were supposed to stay open for the remainder of the project.