[2] In December 2007, Chennai Metro Rail Limited (CMRL) was incorporated and the Government of India gave approval for the project in January 2009.

[4][3] In February 2009, a ₹199 crore (US$23 million) contract was awarded for the construction of a 4.5 km (2.80 mi) long viaduct along the Inner Ring Road between Koyambedu and Ashok Nagar.

[7][8] In January 2011, a joint venture between Larsen and Toubro and Alstom was awarded the contract for design and construction of track works and a depot at Koyambedu for ₹449.22 crore (US$52 million).

[15] In April 2015, the Commissioner of Metro Rail Safety inspected the rolling stock and submitted the report to the Railway Board.

[23] The trains are air-conditioned with electrically operated automatic sliding doors and have a first-class compartment with a dedicated section reserved for women.

In the underground sections, a walkway runs along the length with cross passages every 250 metres (820 ft 3 in) for the maintenance and emergency evacuation.

[37][38] The main operational control center (OCC) is located in Koyambedu where the movement of trains and real-time CCTV footage obtained is monitored.

[39] Chennai Metro maintains a major depot at Koyambedu covering an area of 26 ha (64 acres) which houses maintenance workshops, stabling lines, test tracks and a washing plant for the trains.