However, a major technical glitch that led to evacuation of thousands of passengers in May, many suicides committed in September and 13 metro stations shut down for long hours on December 15 due to violent anti-CAA protests in Delhi also kept the city's beloved rapid transit system in news.
In keeping with its vision to provide convenient, swift and eco-friendly mode of transportation to people, the Delhi Metro began its network expansion in the year with the extension of the old Red Line (Rithala-Dilshad Garden) to neighbouring Ghaziabad.
Prime Minister Narendra Modi on March 8 inaugurated the 9.4-km-long Dilshad Garden-Shahid Sthal (New Bus Adda) section.
With this new section, entirely elevated, the Delhi Metro forayed into the interiors of Ghaziabad for the first time, touching the industrial areas in twin cities of Ghaziabad and Sahibabad.
The next day Modi also flagged off the 6.675-km all-elevated Noida City Centre to Noida Electronic City corridor, an extension of the Blue Line (Dwarka Sec 21-Noida City Centre) via remote.
Delhi also got a brand new corridor -- the Grey Line -- on October 4 when the Dwarka-Najafgarh Metro section was flagged off for passenger operations.
But it wasn't just new construction that kept the Delhi Metro Rail Corporation busy, as the DMRC also in late October took over the operations and maintenance of the 11.6-km Rapid Metro Link in Gurgaon, with an interchange at Sikanderpur station, which connects the corridor with the rest of the Delhi Metro network.
The DMRC was founded in 1995 and on December 24, 2002 began operations with the opening of 8.4-km Shahdara-Tis Hazari corridor.
Several programmes were organised throughout the year by the DMRC at various stations' premises and elsewhere to mark the 25th year of its incorporation.
As on December 24, the total network span stood at 389 km with 12 lines and 285 stations, including Aqua Line (Noida-Greater Noida) and Rapid Metro networks.
In another major development for the Delhi Metro, the Union Cabinet in March approved three out of six corridors of the Delhi Metro's proposed Phase-IV -- Mukundpur-Maujpur, RK Ashram-Janakpuri West and Aero City-Tughlakabad.
There will be 17 underground and 29 elevated stations in the three corridors whose total length will be 61.679 km.
While 2019 saw several highs for the DMRC and authorities tried to make travel as safe as possible for passengers, several incidents of suicides reported at metro station premises in September and other preceding months, prompted Delhi Metro authorities to initiate a campaign -- 'Never Give Up' -- on suicide prevention.
From young to old, at least eight cases of suicides at metro stations were reported from May-September, with five of these occurring in September alone.
Besides, seven other people attempted suicide between April and October, some of whom were battling depression.
One of the first suicide cases was reported on May 1 when a civic agency worker allegedly killed himself by jumping in front of a metro train at the Dwarka Sector 9 station on the Blue Line. In June, a 23-year-old man, who was undergoing treatment for depression for the last two years, had allegedly committed suicide by jumping in front of a moving metro train at the Civil Lines station here, according to police.
Another low for the DMRC during 2019 was in May when a technical glitch on the Yellow Line that disrupted services for at least four hours, leaving thousands of passengers stranded on the road, trapped in coaches and traffic snarls all the way from Gurgaon to New Delhi.
Services were hit due to a breakdown of the overhead wire (OHE) at Sultanpur station, midway between Gurgaon and Delhi, leading to power supply tripping in the section, DMRC officials had said.
In December, Delhi Metro made headlines again amid protests over the amended citizenship law, when several metro stations were closed on instruction of police authorities.
Metro commuters on December 15 faced difficulties as gates of 13 stations were closed due to violence following protest and arson against the CAA in south Delhi.
The entry and exit gates of these stations were shut for several hours in view of the violent protests near New Friends' Colony. In a series of tweets, the DMRC had said entry and exit gates of GTB Nagar, Shivaji Stadium, Patel Chowk, Vishwavidyalaya, Vasant Vihar, Munirka, R K Puram Metro stations were closed on the advice of the police.
Among other accomplishments, the Delhi Metro inaugurated a foot over bridge (FOB) connecting the Durgabai Deshmukh South Campus metro station of Pink Line and Dhaula Kuan metro station of the Airport Express Line for passengers in February.
The FOB is a major technological masterpiece, as a record 22 travelators have been installed on it for the convenience of passengers.
Besides, in November, three leading airlines -- Air Asia, SpiceJet and Go Air -- started check-in facility from the New Delhi metro station of the Airport Line. Two other airlines -- Air India and Vistara -- are already operating this facility.