Kolkata

Kolkata  is the capital of the Indian state of West Bengal. Located on the east bank of the Hooghly river, it is the principal commercial, cultural, and educational centre of East India, while the Port of Kolkata is India's oldest operating port as well as its sole major riverine port. As of 2011, the city had 4.5 million residents; the urban agglomeration, which comprises the city and its suburbs, was home to approximately 14.1 million, making it the third-most populous metropolitan area in India. As of 2008, its economic output as measured by gross domestic product ranked third among South Asian cities, behind Mumbai and Delhi. As a growing metropolitan city in a developing country, Kolkata confronts substantial urban pollution, traffic congestion, poverty, overpopulation, and other logistic and socioeconomic problems.

Public transport is provided by the Kolkata Suburban Railway, the Kolkata Metro, trams, and buses. The suburban rail network reaches the city's distant suburbs. The Kolkata Metro, in operation since 1984, is the oldest underground mass transit system in India. It spans the north–south length of the city and covers a distance of 25.1 km (16 mi).

Kolkata Metro

 As of 2009, five Metro rail lines were under construction. Kolkata has three long-distance railway stations, located at Howrah, Sealdah, and Chitpur, which connect Kolkata by rail to most cities in West Bengal and to other major cities in India. 
The city serves as the headquarters of two Indian Railways regional divisions—the Eastern Railway and the South-Eastern Railway.

Buses, which are the most commonly used mode of transport, are run by government agencies and private operators.

Calcutta Tramways

 Kolkata is the only Indian city with a tram network, which is operated by the Calcutta Tramways Company. The slow-moving tram services are restricted to certain areas of the city.

Calcutta State Transport Corporation

The Kolkata Metro has somewhat eased traffic congestion, as has the addition of new roads and flyovers. Agencies operating long-distance bus services include Calcutta State Transport Corporation, South Bengal State Transport Corporation, North Bengal State Transport Corporation, and various private operators. 

Netaji Subhash Chandra Bose International Airport, located in Dum Dum some 16 km (9.9 mi) north-east of the city centre, operates domestic and international flights.

Netaji Subhash Chandra Bose International Airport

 As of 2011, the airport was being upgraded to handle increased air traffic.