Mount Washington Transit Tunnel Closes Through Monday

Pittsburgh Regional Transit will close the Mount Washington Transit Tunnel from the end of service on Friday, October 2, through the start of service on Monday, October 5, to finish remaining work from its 2025 reconstruction. The agency posted the window on September 29 in its news releases, naming the same Allentown and Wabash Tunnel detours riders used during earlier remaining-work weekends.

Anyone riding the T or a South Hills bus into Downtown this weekend should add extra time and follow the posted detour, not the usual tunnel path between South Hills Junction and Station Square. Travelers pairing a downtown stay with neighborhood sightseeing can still use the visitor map in our Pittsburgh things to do guide, then check PRT before they leave.

Weekend Closure Window for PRT Riders

The tunnel is the only one in the United States that carries both buses and light-rail vehicles, and it is the direct link between South Hills Junction and Station Square Station just south of Downtown. When it is closed, every Red, Blue, and Silver Line trip that would normally punch through Mount Washington has to leave that corridor, and so do the bus routes that share the same tube.

PRT’s September 29 notice is the current operating order for this weekend, not a leftover from the long 2025 shutdown. Riders should treat Friday night as the start of the outage and Monday’s first trips as the return to the tunnel, unless a later alert changes the clock. The agency also points riders to rideprt.org/Detours/ for route-level maps once they know which line or bus they need.

Customer questions go to PRT at 412-442-2000, on X at @PghTransitCare, or through live chat on rideprt.org. Those channels matter more than a screenshot of last year’s rebuild page, because the project site still leads with the December 2025 reopening and does not replace this weekend’s dated notice.

Light Rail Detours Through Allentown

During the closure, all inbound and outbound light-rail service will detour through Allentown. That is the same surface alignment along Warrington and Arlington avenues that carried the T in 2025 and on remaining-work weekends this spring.

A rail shuttle will operate between the outbound platform of Station Square and Allegheny Station so the Downtown and North Shore subway spine stays in service. Riders who usually board at Station Square for a South Hills trip should take the Allentown detour or a posted connection, not wait for a through car on the tunnel track.

If you are connecting to a hotel check-in or a flight from Pittsburgh International, build the 20-minute pad into the first transfer. The same weekend also overlaps other Pittsburgh road work, including the I-376 Grant Street ramp shutdown, so a missed T trip is harder to replace with a quick rideshare.

Bus Reroutes via Allentown and the Wabash Tunnel

Bus service is detoured as well. Inbound buses will generally use Allentown streets, while outbound service will use the Wabash Tunnel. That split keeps most South Hills buses moving toward Downtown without sending both directions through the same narrow hill streets at once.

The notice does not list every route number in the weekend headline, which is why the detours index is the working document. A rider on a South Hills Flyer-style route, a local that usually ducks into the transit tunnel, or a trip that only uses the tube at one end should open the route card before Saturday morning, not after the bus has already turned.

Expect bunching on Warrington Avenue, Arlington Avenue, and the Wabash Tunnel approaches, especially around event times at Station Square. If you are staying on Mount Washington itself, the neighborhood’s passenger inclines are a separate system from this tunnel. The Monongahela Incline visitor guide and the Duquesne Incline visitor guide remain the right next read for that hillside access, and they do not replace a T or bus ticket through the transit tunnel.

Remaining 2025 Rebuild Work

The weekend outage is leftover construction, not a new eight-month shutdown. PRT closed the tunnel on February 23, 2025, to replace more than 1,000 feet of light-rail track plus the roadway and overhead lines, a job then estimated at about $28 million, and restored regular service on Christmas Day 2025 after a design delay.

After that reopening, remaining work still required short weekend closures. WPXI reported in May 2026 that PRT planned two such weekends, using the same Allentown rail detour, Station Square to Allegheny shuttle, inbound Allentown buses, outbound Wabash Tunnel buses, and a 20-minute delay warning.

This October window follows that remaining-work pattern, with dates from PRT’s September 29 release rather than the May calendar. The current order is Friday night through Monday morning only, unless PRT posts a follow-on notice.

Rider Checks Before Saturday Service

Start with the line or bus you actually hold a ticket for, then read that route’s detour. Light-rail riders should confirm whether their trip uses the Allentown surface tracks, the Station Square to Allegheny shuttle, or both. Bus riders should confirm inbound versus outbound, because those two directions are not on the same hill road.

PRT advises riders to expect delays of up to 20 minutes during the planned detour. Allow time for your actual connection and keep airline check-in and boarding deadlines. For a future trip moved off Saturday or Sunday, consider Monday only after PRT confirms regular service has resumed. Use TrueTime and the detours page for current routing; the scheduled return is not an observed reopening.

Do not treat a neighboring road closure as proof that your bus is canceled. Other Pittsburgh construction this week may slow cars, but it does not rewrite PRT’s rail and bus plan unless the agency says so on the detour card for your route.