By Lynne Adkins

PHILADELPHIA (CBS)  —  Starting today, SEPTA is closing a key bridge that carries the Norristown high speed line.

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The Bridgeport Viaduct was built in 1911 and is the bridge that carries the Norristown High Speed line over the Schuylkill River.

SEPTA Spokeswoman Heather Redfern says it will undergo a four-month construction project and shuttle buses will be used between the Norristown Transportation Center and Bridgeport station.

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“It might add to the trip because instead of being above traffic on the bridge, you’ll be on the street with the buses, but we are doing the best we can with the shuttles and will adjust the schedule as needed to best service our passenger,” Redfern explained.

Some 2,400 daily passengers will be impacted.

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Redfern says the $7.5 million construction project will allow crews to replace timber and the track and do minor repairs.