Project Profile: Second Avenue Subway (SAS) Phase 2, New York

The Second Avenue Subway (SAS) Phase 2 is a critical infrastructure project extending New York City’s Q line subway service approximately 1.5 miles north into East Harlem. This extension is engineered to alleviate severe congestion on the adjacent Lexington Avenue Line and establish a modern, high-capacity transit corridor. The project involves complex tunneling operations and system integration within one of the world’s densest urban environments.

Technical Specifications

The project’s scope includes the northern extension of the Q line from its current terminus at 96th Street to 125th Street. The route will feature three new, fully ADA-compliant stations at 106th, 116th, and 125th Streets, equipped with modern accessibility features like elevators and escalators. Tunneling will be executed primarily using a Tunnel Boring Machine (TBM), leveraging existing tunnel segments constructed in the 1970s. Station construction will employ cut-and-cover methods, requiring extensive utility relocation and careful management of surface-level disruption. A key engineering challenge is the integration at 125th Street, creating a seamless interchange with the Lexington Avenue Line (4, 5, 6 trains), Metro-North Railroad, and the M60 Select Bus Service. The project also encompasses the installation of modern signal systems, communications networks, power substations, and ancillary facilities.

Key Takeaways

• Congestion Relief: Directly addresses chronic overcrowding on the Lexington Avenue Line, the most heavily used rapid transit line in the United States, by providing a parallel service route.
• Economic Catalyst for East Harlem: Expected to significantly boost economic development by improving access to jobs, services, and educational institutions, while reducing commute times by up to 20 minutes for area residents.
• Strategic Multimodal Hub: The 125th Street station is designed as a major transit nexus, integrating subway, commuter rail, and bus services to enhance regional mobility and provide resilient transportation options.

Frequently Asked Questions (FAQ)

When will the Second Avenue Subway Phase 2 open?

The Metropolitan Transportation Authority (MTA) projects that the Second Avenue Subway Phase 2 extension will be completed and operational between 2030 and 2032, pending final funding allocation and construction timelines.

Who is building the Second Avenue Subway Phase 2?

The project is led by the Metropolitan Transportation Authority (MTA). Key partners include a joint venture of WSP and STV providing final engineering and design services, following the preliminary design work completed by an AECOM-Arup joint venture.