The detailed project report (DPR) for the Metro Rail extension from Koyambedu to Avadi will be completed this month, and the Chennai Metro Rail Limited (CMRL) is also conducting a feasibility study to extend the line to Pattabiram. After submitting the detailed feasibility report (DFR) on extending the network from Koyambedu to Avadi as part of corridor 5 (Madhavaram – Sholinganallur) in phase II in September 2023, CMRL had entrusted the DPR preparation to RITES in July 2024. 

"The DPR is in the final stage till Avadi and the feasibility till Pattabiram is also being studied as recommended. The peak hour peak direction (PHPD) traffic in Pattabiram is reaching the ideal standard of 12,000 passengers per hour. If feasible, the report will be submitted to the government in a month," said an official. 

The approximate alignment length from Koyambedu to Avadi is 16.1 km, which will increase to nearly 20 km if the stretch is extended till Pattabiram. The estimated cost of construction is Rs 65 billion. 

"About 15 elevated stations are being planned on the stretch, and additional stations are likely if it is extended till Pattabiram," the official added. The depot will be constructed in Avadi or in a vacant space near Outer Ring Road (ORR) in Pattabiram. 

Some of the important stations likely in the stretch are Koyambedu, Padi Pudhu Nagar, Wavin, Ambattur Estate bus stand, Ambattur railway station, Tirumullaivoyal, Avadi railway station, and a station either in Tirumangalam or Mogappair.