The original station at this location is the Shuttle (S) station. The original subway ran from City Hall Station (a loop station south of today’s Brooklyn Bridge Station) on the east side (today’s 4, 5, 6 trains) to just north of 33^rd Street where it turned unto what is now the Shuttle tracks and ran to Longacre Square (the original name of Times Square before the New York Times built their building at the location) using today’s Shuttle stop as the station and then turned up the west side on today’s 1 train route to 145^th Street and Broadway with a branch to the Bronx zoo (Today’s 2 and 3 trains). When the lines were extended South on the West side and Northward on the East side today’s configuration of Grand Central IRT was born. This entire complex has been renovated including the railroad terminal which was saved from being demolished after the public outcry over the destruction of Penn Station Railroad Station in favor of office buildings and a newer Madison Square Garden and a three level basement railroad station.

Ignoring the railroad, the IRT 7 is the deepest and the shuttle the shallowest of the lines a this complex

Grand Central (4, 5, 6) has two island platforms and multiple crossovers and crossunders . The crossovers connect to the shuttle to Times Square and Metro North as well as the 7 line while the crossunders connect to the 7 line. This station is unique in having the only air conditioned subway station in the NYCT system thanks to a renovation of the railroad Station and a new cooling system having the extra capacity for the chilled water. The chilled water is piped into air handlers where a fan blows the cooled air into the subway via noisy overhead units. The ambient temperature is reduced by ten degrees and is a popular waiting spot during hot summer days. The Mezzanine also has escalators to the railroad terminal above and features a compass on the floor which is geographically accurate. The passageway to the Shuttle platform as well as the Mezzanine features shops and newsstands. Artwork just inside the shuttle passageway and facing the mezzanine "Fast Track and Speed Wheel" by by Dan Sinclair depicts stylized steam locomotives in the tile band with brass 4,5,6, and 7 numerals evenly spaced. Accessing the 7 via the crossunders lead to a lower Mezzanine and then two escalators (with a landing) to the 7. The 7 can also be accessed via a single long escalator from the upper Mezzanine. The station also has vent chambers in the track walls and a low tiled curtain wall separating northbound and southbound tracks. Columns are also tiled.