178th–179th Street Tunnels

Originally conceived and constructed under the auspices of Robert Moses, the twin tunnels have been superseded by the Trans-Manhattan Expressway in Washington Heights, which itself runs through a cut with high-rise apartments built over it in places.

The eastern end split into two directions: a ramp to Amsterdam Avenue on the right and a 1,000-foot-long (300 m) driveway south to the Harlem River Drive on the left.

[4] After delays related to the construction of the Harlem River Drive ramp,[5] the 178th Street Tunnel opened on June 27, 1940, serving both directions of traffic.

[2] Due to labor shortages and low traffic during World War II, the tunnel was closed in May 1942, reopening in November 1945.

[13] Following the closures, the entranceway of the 178th Street Tunnel was used as a secondary emergency equipment garage for the George Washington Bridge but later removed.

A study was completed, in which the tunnels would be rehabilitated and reused temporarily for traffic diverted from a reconstruction of the Trans-Manhattan Expressway and the Alexander Hamilton Bridge.