Transporting more than 8.5 million people in the city that never sleeps is a challenge. The 24 subway lines operated by the Metropolitan Transportation Authority (MTA) are frequently congested during morning and evening rush hours. Commuters living on Manhattan’s far East Side lacked a direct subway line, resulting in a surplus of riders on the Lexington Avenue Subway’s 4, 5 and 6 trains, which in turn caused delays and safety risks in bottlenecked stations.

In an effort to relieve excessive crowding and stress on the entire system’s infrastructure, MTA commissioned the AECOM-Arup Joint Venture (AAJV) as the prime engineering and design consultant for the new Second Avenue Subway (SAS) — the first major expansion of the New York City Transit (NYCT) subway system in over 50 years.

This US$4.45 billion first-phase expansion runs 1.8 miles between 63rd and 96th streets and consists of three new stations at 72nd, 86th and 96th streets, plus one upgraded station at 63rd Street. Completion of this project required a comprehensive approach that extended beyond conventional engineering, with an eye toward devising new standards for underground tunneling and station design.