Designed to make travel smoother by transporting masses of people for short to medium distances at high frequency in urban and suburban spaces, the metro system, also known as the subway, underground or the tube, has been operational since the 19th century when the Metropolitan Railway (now part of The London Underground) opened in London in 1863.

The Kolkata metro was conceived as the panacea to the ills of surface transportation in the city, where roads accounted for a little over four percent of the surface area. A blueprint was prepared in 1971 with the help of USSR, and engineers from East Germany to construct five rapid transit lines in the city. The project was finally flagged off in 1984 after a decade of delays. In 2010, the Kolkata Metro became the 17th zone of the Indian Railways and is operated by the Ministry of Railways.