7. East Side Access tunnel

Photo by the MTA from Flickr.

East Side Access will provide direct LIRR service into a new concourse below Grand Central Terminal on the East Side of Manhattan, which could reduce commutes by nearly 40 minutes. Although not as secret as other tunnels on this list, East Side Access will include more than eight miles of tunneling. The project will help reduce passenger crowding, train congestion and automobile traffic. Passengers traveling from Midtown East will have easier access to JFK International Airport via the AirTrain at the LIRR Jamaica Station. When completed, East Side Access will serve approximately 162,000 customers a day.

Project teams excavated dense bedrock beneath Manhattan and the mixed face soil under Queens to make room for new train tunnels, platforms and service facilities and ventilation and access shafts. Additionally, a new terminal with eight tracks, four-passenger platforms, mezzanines and concourses has been constructed. Teams are also building a 350,000 square foot passenger concourse directly below the lower level of Grand Central Terminal.