Sections of SEPTA's Norristown High Speed Line and Regional Rail's Manayunk/Norristown Line will have buses shuttle passengers between stations from August until late December. The adjustments are part of SEPTA's ongoing rehabilitation of the Bridgeport Viaduct, officials said.

The service changes mark the second phase of SEPTA's project to repair the bridge that carries the Norristown High Speed Line over the Schuylkill River in Montgomery County. The steel viaduct was built in 1911 and is SEPTA's third-oldest span. About 1,900 people cross it on SEPTA's M Line every weekday. The first phase of the project required shuttle buses from late March into May.

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The second round of service adjustments starts Friday and will continue with the following schedule over the coming months:

• Aug. 1-Aug. 21: Bus service will be provided between Norristown Transit Center and Bridgeport Station. Train service will operate on a normal schedule between Bridgeport Station and 69th Street Transit Center.
• Aug. 15-Aug. 23: Shuttle buses will be used on Regional Rail's Manayunk-Norristown Line from Norristown-Elm Street Station to Norristown Transit Center. Train service will operate as normal from Norristown Transit Center to Center City.
• Aug. 22-Aug. 30: Bus service will be provided between Norristown Transit Center and Gulph Mills Station. Train service will operate as normal between Gulph Mills Station and 69th Street Transit Center.
• Aug. 31-Dec. 19: Bus service will be provided between Norristown Transit Center and Bridgeport Station. Train service will operate as normal between Bridgeport Station and 69th Street Transit Center.

SEPTA said riders should plan for longer travel times.

The Bridgeport Viaduct project includes work to repaint the entire viaduct, replace its deck, complete structural bridge repairs and repair sidewalks at Norristown Transit Center. SEPTA said the project was planned in phases to avoid service disruptions during the World Cup, the city's celebrations for the nation's 250th anniversary and the MLB All-Star Game. The third phase of the project will take place with additional service adjustments in early 2027.