MTA Begins Environmental Review of 125 Street Subway Tunnel Extension

The Metropolitan Transportation Authority (MTA) on Oct. 8 announced the release of the draft scoping document and opening of the public comment period for the planned 125 Street Subway Tunnel Extension. Second Avenue Subway (SAS) Phase 2, currently under construction, will extend the Q Line from its current terminus at 96 Street with three new stations, ending at 125 Street & Lexington Ave. Phase 2 will utilize two massive tunnel boring machines (TBMs) that will end their run under West 125 Street between Lenox and Adam Clayton Powell Jr. Avenues.  

This presents a unique opportunity to make use of these machines to build the tunnel for a future crosstown subway under 125 Street. By continuing westward, the 125 Street Subway Tunnel Extension would facilitate future crosstown subway service with transfer stations at Lenox Ave (2-3 trains), St. Nicholas Ave (A-C-B-D trains), and Broadway (1 train).

The future extension, first identified in the MTA’s last 20-Year Needs Assessment, would greatly improve travel across 125 Street – the busiest crosstown bus corridor in Manhattan. It would connect to seven subway lines and Metro-North while giving Harlemites a one-seat ride to jobs, health care, and other destinations on Manhattan’s East Side and West Sides.   

Reusing the tunnel boring machines from SAS Phase 2 could save taxpayers hundreds of millions while speeding tunnel construction by more than two years. 

“Given the huge potential to save time and money, it would be irresponsible not to explore options to keep digging westward under 125 St,” said MTA Chair and CEO Janno Lieber. “And we are of course making it a priority to get community input and feedback as we kick off the environmental review process.”  

“The 125 St tunnel extension is another example of the MTA’s commitment to explore ways to deliver upgrades better, faster, and cheaper—saving time and money by reusing the tunnel boring machines already in motion for the Second Avenue Subway.” said President of MTA Construction & Development Jamie Torres-Springer. “With environmental review now underway, we’re beginning the critical process of hearing directly from the communities that would most benefit from a new crosstown connection.”  

Funding to advance the project’s feasibility study was included in Governor Kathy Hochul’s FY 2026 budget which also included an amendment to the State Environmental Quality Review Act (SEQRA) that allows early design work and engineering on the tunnel to proceed while an environmental review is underway, speeding up the completion timeline significantly. 

Planning for the 125 Street tunnel extension began in 2024, when Governor Hochul and the State Legislature funded a feasibility study, which concluded the project is achievable and beneficial. The project would construct the new subway tunnel beneath West 125 Street, with subway infrastructure like tracks, signals, and stations to be designed and constructed at a later stage. Environmental review is now underway to study how the proposed tunnel construction would impact the surrounding community and environment. 

The scoping document released the specific topics, issues, and potential impacts that will be formally analyzed during environmental review. The public comment period, which runs through Nov. 13, gives community members and stakeholders the opportunity to provide input on the content of the scoping document and ensure the environmental review is comprehensive and reflective of community concerns and desires. The Draft Environmental Impact Statement (EIS) is expected to be released in the first quarter of 2027. 

The MTA will host a series of public comment sessions to solicit community feedback on the draft scope of work:  

• Thursday, Oct. 22: noon to 2:00 p.m. and 6:00 p.m. to 8:00 p.m.: Virtual via Zoom 
• Tuesday, Oct. 27: 6:00 p.m. to 8:00 p.m. at Adam Clayton Powell Jr. State Office Building, 2nd Floor Community Room, 163 W 125 Street, New York, NY 10027 

Members of the public can also submit comment via regular mail to MTA Government & Community Relations, Attn: 125 Street Subway, 2 Broadway, D16.94, New York, NY 10004, or online at http://mta.info/project/125-street-subway