Public transportation in Delhi is provided by auto rickshaws, buses, rapid transit system, taxis and suburban railways. Buses are the most popular means of transportation catering to about 60% of the total demand.[24] Major bus service providers include state-owned Delhi Transport Corporation (DTC), BlueLine Transport Corporation and several other private concerns. Private vehicles account for 30% of the total demand for transportation while the rest of the demand is met largely by auto-rickshaws, taxis, rapid transit system and railways.[24]

Transportation in Delhi is largely dependent upon road. Railways, including rapid transit systems like Delhi Metro, serve only 1% of the total demand. Major railway stations are Old Delhi, Hazrat Nizamuddin and New Delhi Railway Station. Road transportation in Delhi is maintained by MCD, NDMC, Delhi Cantonment Board, Public Works Department and Delhi Development Authority. At 1749 km of road length per 100 km², Delhi has one of the highest road densities in India. Major roadways include the Ring Road and the Outer Ring Road which had a traffic of 110,000 vehicles per day in 2001. Delhi is well connected to other parts of India by 5 National Highways: NH-1, -2, -8, -10 and -25. In 2001, more than 3.45 million vehicles were plying on Delhi's roads and the demand for transportation rose by 6.7% while the number of motor vehicles in Delhi rose by 14.7%[24].

A completed portion of the still-in-progress Delhi Metro.Delhi's high population growth rate, coupled by high economic growth rate has resulted in ever increasing demand for transportation creating excessive pressure on the city's existent transport infrastructure. Like many other cities in the developing world, the city faces acute transport management problems leading to air pollution, congestion and resultant loss of productivity. In order to meet the transportation demand in Delhi, the State and Union governmet started the construction of an ambitious mass rapid transit system, known as Delhi Metro. As of 2005, the metro operates 3 lines with a total length of 156 km and 150 stations while several other lines are under construction. The MCD and PWD also launched several traffic decongestion programmes. In 2001, the MCD alone started the construction of 21 flyovers at busy intersections throughout Delhi.[25]

Due to high traffic congestion, Delhi's pollution levels increased drastically during the mid-1990s. In 1998, the Supreme Court of India ordered all public transport vehicles, including buses, taxis and auto-rickshaws, to use compressed natural gas as fuel instead of diesel and other hydro-carbons. The DTC now operates the world's largest fleet of environmentally friendly CNG buses.[26] Though pollution due to road transportation has decreased in recent years, it remains alarmingly high. Besides expanding the Delhi Metro, the government is currently considering several other means such as Trolleybus, Monorail and Integrated Freight Complexes to meet transport demand and reduce traffic congestion and pollution levels in the city.[25]

Indira Gandhi International Airport (IGI) serves Delhi for both domestic and international connections, and is situated in the southwestern corner of the city. In 2004, IGI recorded a traffic of more than 8.5 million passengers,[27] making it one of the busiest airports in South Asia. Two other airports are Palam (now part of the IGI complex) and Safdarjung Flying Club.