Sep 17, 2014 By David Singer 1 min read

Port Authority is announcing Red Line T service will be detoured in both directions so crews can replace the light rail grade crossing at Potomac Avenue.

The detour and related street closure starts at 7 p.m. Sept. 19, and continues around-the-clock all weekend. Regular routing will resume in time for the morning commute on Sept. 22, Port Authority spokeswoman Heather Pharo said.

Potomac Avenue will be closed at Broadway Avenue during the rail work, and traffic detour signs will be posted.

All Red Line stops between Overbrook Junction and South Hills Junction will be affected.

Red Line service will detour via the Blue Line’s routing between Willow Station-Overbrook Junction and South Hills Junction.

Rail shuttles will operate between Overbrook Junction and Dormont Junction, as well as between Shiras and South Hills Junction. Bus shuttles will operate between Mt. Lebanon Station and Fallowfield. Due to street closures, buses will not be able to serve Potomac Station or Stevenson. Riders will need to go to West Liberty Avenue for service, where they may catch the bus shuttle or 41 Bower Hill route.