Commuters who use the Norristown High Speed Line through Whitemarsh and Plymouth townships will need to budget extra travel time starting Aug. 1. SEPTA announced Monday that shuttle buses will replace train service on portions of the M Line for 20 consecutive weeks as crews tackle the second phase of a three-phase, $55 million rehabilitation of the Bridgeport Viaduct.

The disruption runs through Saturday, Dec. 19, and directly affects riders at Norristown Transit Center and Gulph Mills Station.

Phased busing schedule

SEPTA is splitting the work into segments, each with its own bus-replacement zone:

  • Aug. 1–21: Buses replace trains between Norristown Transit Center and Bridgeport Station. Normal train service continues from Bridgeport to 69th Street Transit Center.
  • Aug. 22–30: Buses replace trains between Norristown Transit Center and Gulph Mills Station. Normal service continues from Gulph Mills to 69th Street.
  • Aug. 31–Dec. 19: Buses again replace trains between Norristown Transit Center and Bridgeport Station.

A separate Regional Rail shuttle will also run on the Manayunk/Norristown Line from Saturday, Aug. 15, through Saturday, Aug. 23, replacing trains between Norristown–Elm Street Station and Norristown Transit Center.

Why the work is happening

The Bridgeport Viaduct is a 3,525-foot bridge built in 1911 that carries the M Line over the Schuylkill River. Nearly 1,900 of the line's 5,600 weekday riders cross it daily, according to SEPTA.

Contractor J.D. Eckman is handling the construction, which includes repainting the entire viaduct, replacing lacing bars, rivets, bolts, and bearings, repairing the concrete substructure, replacing the concrete deck, and fixing sidewalks at Norristown Transit Center.

SEPTA General Manager Scott A. Sauer said at the project's March 27 kickoff that the work was phased specifically to avoid a major outage during the summer's FIFA World Cup matches, MLB All-Star Game, and America's 250th birthday celebration in Philadelphia.

"This 115-year-old viaduct is SEPTA's third-longest bridge, and this work is needed for us to be able to continue M service between Bridgeport and Norristown," Sauer said at the March event.

What riders should know

SEPTA advises passengers to plan ahead for bus-to-train connections at affected stations and expect longer travel times. Real-time shuttle bus information will be available through the SEPTA trip planner at plan.septa.org. The shuttle trips will not appear on the standard M Line or Norristown Line schedule pages.

A PDF schedule for the Norristown Transit Center–Bridgeport Station segment is posted on septa.org. The Gulph Mills schedule was listed as "available soon" as of Monday, July 20.

The first phase of the project ran from Saturday, March 29, through Saturday, May 9, and has been completed. A third and final outage is planned for Sunday, Jan. 18, through Saturday, Feb. 6, 2027.

Riders with questions can reach SEPTA customer service at 215-580-7800, Monday through Friday from 7 a.m. to 7 p.m. and Saturday through Sunday from 8 a.m. to 5 p.m.