Reusing two Second Avenue Subway Phase 2 tunnel boring machines could save taxpayers hundreds of millions of dollars and shave more than two years off the proposed 125 Street Subway Tunnel Extension, the MTA said as it launched public scoping on the project.

The MTA also released a draft scoping document and opened a public comment window that runs through Nov. 13. The Draft Environmental Impact Statement is targeted for the first quarter of 2027.

What does reusing the TBMs actually change?

The MTA pegs the savings at "hundreds of millions" of dollars and more than two years of construction time versus a standalone tunnel job. Those numbers trace to one decision: keep the machines in the ground heading west instead of pulling them out after Phase 2 wraps.

The Phase 2 program extends the Q Line from its 96 Street terminus to 125 Street and Lexington Avenue, adding three new stations. TBM extraction is planned under West 125 Street between Lenox and Adam Clayton Powell Jr. Avenues — the exact point the new extension would keep boring from.

What service would the new tunnel carry?

The crosstown line would deliver a one-seat ride between Harlem's western blocks and the East Side, with transfer stations at:

• Lenox Avenue (2/3 trains)
• St. Nicholas Avenue (A/C/B/D trains)
• Broadway (1 trains)

It would also tie into seven subway lines and Metro-North Railroad — stitching together riders on what the MTA calls the busiest crosstown bus corridor in Manhattan.

Why this corridor, why now?

The extension first surfaced in the MTA's last 20-Year Needs Assessment. A continuous tunnel would replace today's forced-transfer pattern through 125 Street surface routes with a single ride to jobs, health care and other destinations on Manhattan's East Side and West Side.

Where does the money and authority sit?

New York Gov. Kathy Hochul's fiscal 2026 state budget funded a feasibility study for the extension. Planning kicked off in 2024 when the governor and state legislature set that study in motion; it has concluded the project is achievable and beneficial. The same FY26 package amended the state Environmental Quality Review Act so early design and engineering can run in parallel with the environmental review, rather than waiting for it to clear.

What is MTA leadership saying?

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

What happens after Nov. 13?

The scoping document lays out the topics, issues and potential impacts the review will analyze. Stakeholders have until that date to weigh in before the agency advances toward the Draft EIS in Q1 2027.

"The 125 Street 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 Construction and Development President Jamie Torres-Springer.

If the schedule holds, the TBMs extracting from Phase 2 under Lenox and Adam Clayton Powell Jr. Avenues could keep boring straight west into a crosstown tube that, by Q1 2027's draft document, finally has a defined footprint on the page.