The Second Avenue Subway (SAS) project is to include a two‐track line along Second Avenue from 125th Street to the Financial District in Lower Manhattan. It is also to include a connection from Second Avenue through the 63rd Street tunnel to existing tracks for service to West Midtown and Brooklyn. Under the current plan, the project is being built in four phases. Phase One includes tunnels from 105th Street and Second Avenue to 63rd Street and Third Avenue, with new stations along Second Avenue at 96th, 86th and 72nd Streets and new entrances to the existing Lexington Avenue/63 Street Station at 63rd Street and Third Avenue.

The Maintenance and Protection of Traffic (MPT) plans related to the 63rd Street Station had been developed and needed to be analyzed in conjunction with other ongoing projects in the area. These included the construction related to the Third Water Tunnel (TWT) and 1st Avenue/2nd Avenue BRT (Bus Rapid Transit) projects.

Based upon discussions amongst New York City Department of Transportation (NYCDOT), DMJM Harris Arup (DHA), Metropolitan Transportation Authority Capital Construction (MTACC), KLD was directed to extend the model developed for the QBB TWT work for NYCDOT.

The ‘SAS model’ was developed covering 48th Street to 72nd Street, and York Avenue/Sutton Place to Fifth Avenue including the connecting ramps to and from the FDR. This model was used to assess impacts during weekday AM, weekday PM and weekend peak period conditions, concentrating on the peak hour. Supplemental data collection was done, and the data incorporated into the calibrated model. Existing information on the bus routes and schedules, signal timing, network geometrics, and origin‐destination patterns were incorporated into the model. Recommendations were provided for the MPT plans based on the findings of the analysis. The tools used in the analyses included Aimsun, Synchro/SimTraffic and HCS.