[23] Over the next several years, committees in a number of government departments were commissioned to examine issues related to technology, route alignment, and governmental jurisdiction.

[24] The city expanded significantly while technical studies and financing the project underway, doubling its population and increasing the number of vehicles five-fold between 1981 and 1998.

[24] Traffic congestion and pollution soared as an increasing number of commuters used private vehicles, and the existing bus system was unable to bear the load.

[23] A 1992 attempt to privatise the bus transport system compounded the problem, with inexperienced operators plying poorly-maintained, noisy and polluting buses on lengthy routes; this resulted in long waiting times, unreliable service, overcrowding, unqualified drivers, speeding and reckless driving[25] which led to road accidents.

[30] To avoid problems experienced by the Kolkata Metro, which witnessed substantial delays and ran 12 times over budget due to "political meddling, technical problems and bureaucratic delays", the DMRC was created as a special-purpose vehicle vested with autonomy and power to execute the large project which involved many technical complexities in a difficult urban environment within a limited time frame.

Putting the central and state governments on an equal footing gave an unprecedented level of autonomy and freedom to the company, which had full powers to hire people, decide on tenders, and control funds.

[40] A 64.75 kilometer (40.23 miles) network of 59 stations was constructed in Delhi, encompassing the initial sections of the Red, Yellow, and Blue Lines.

At the end of Phases I and II, the network's total length was 188.05 km (116.85 mi) and 145 stations became operational between 4 June 2008 and 27 August 2011.

[86] Over 20 tunnel-boring machines were used simultaneously to expedite construction,[87] which was completed in March 2019 (except for a small stretch due to non-availability of land).

[102][103] On 19 October 2008, a launching gantry and part of the overhead Blue Line extension under construction in Laxmi Nagar collapsed and fell on a passing bus.

[117] On 23 April 2018, five people were injured when an iron girder fell off the elevated section of a Metro structure under construction at the Mohan Nagar intersection in Ghaziabad.

[118] The Haryana Mass Rapid Transit Corporation (HMRTC) has plans to establish a metro network spanning 188 kilometers in Gurugram.

[159] A branch of the Blue Line, inaugurated on 8 January 2010, runs for 6.25 kilometres (3.88 mi) from the Yamuna Bank station to Anand Vihar in East Delhi.

The elevated line, built as part of Phase II, runs primarily along the busy NH 10 route in West Delhi.

On 6 August 2012, to improve commuting in the National Capital Region, the government of India approved an extension from Mundka to Bahadurgarh in Haryana.

A 14 km (8.7 mi) extension south to Escorts Mujesar in Faridabad was inaugurated by Prime Minister Narendra Modi on 6 September 2015.

[169] All nine stations on the Badarpur–Escorts Mujesar (Faridabad) section of the metro's Phase III received the highest rating (platinum) for adherence to green-building norms from the Indian Green Building Council (IGBC).

The final section, between Mayur Vihar Pocket I and Trilokpuri Sanjay Lake, was opened on 6 August 2021 after delays due to land-acquisition and rehabilitation issues.

[63] Most of it was completed on 5 April 2019, except for a small section of the Pink Line between the Mayur Vihar Pocket 1 and Trilokpuri Sanjay Lake stations[193] (opened on 6 August 2021) the Grey Line extension from Najafgarh to Dhansa Bus Stand[194] (opened on 18 September 2021) and the Airport Express extension from Dwarka Sector 21 to Yashbhoomi-Dwarka Sector 25 (Completed on 17th September 2023).

[205] Over 7,000 CISF personnel have been deployed for security in addition to metal detectors, X-ray baggage-inspection systems, and detection dogs.

[246] * Includes Rapid Metro Gurgaon ^ From 2019 onwards the DMRC changed the ridership calculation to count every trip taken by a passenger on a line.

Some depots, such as Shastri Park and Yamuna Bank, are near their respective at-grade station complexes; others, such as Sarita Vihar and Mundka, are joined indirectly to the main line.

The Phase III Kalindi Kunj and Vinod Nagar depots were built differently due to land-acquisition issues; the former has an extra elevated stabling yard adjacent to the Jasola Vihar - Shaheen Bagh station, and the latter has two sub-depots (one with two floors).

[281] The coaches are air-conditioned, equipped with automatic doors, microprocessor-controlled brakes and secondary air suspension,[282] and can maintain an average speed of 32 km/h (20 mph) over a distance of 1.1 km (0.68 mi).

[280] Phase II rolling stock is supplied by Bombardier Transportation, which received an order for 614 cars at a cost of about US$1.1 billion.

Coaches have closed-circuit television (CCTV) cameras with eight-hour backup, chargers for cell phones and laptops, and improved climate control.

[281] The trains, with CCTV cameras in and outside the coaches, chargers for mobile phones and laptops, improved climate control and microprocessor-controlled disc brakes,[287] will be capable of maintaining an average speed of 34 km/h (21 mph) over a distance of 1.1 km (0.68 mi).

Trains have an event recorder which can withstand high levels of temperature and impact, and wheels have a flange-lubrication system for reduced noise and improved comfort.

[290] A 380 MHz digital trunked TETRA radio communication system from Motorola Solutions is used on all lines to carry voice and data information.

[316] Delhi-6, Love Aaj Kal, PK, and Paa also have scenes filmed inside Delhi Metro trains and stations.