Chennai Metro Rail Limited (CMRL) has made significant progress towards enhancing urban transportation by submitting a revised Detailed Project Report (DPR) for the metro extension from Chennai Airport to Kilambakkam bus terminus. The updated proposal, which includes the integration of the metro line with an elevated road, is estimated to cost Rs 9,335 crore—an increase of Rs 5,000 crore from the original estimate.

CMRL Managing Director, MA Siddique, presented the 15.46 km metro extension DPR, which features 13 stations, to K Gopal, Additional Chief Secretary of the Special Initiatives Department. The initial DPR was revised following directives from authorities to incorporate an elevated road alongside the metro corridor.

In the revised plan, the metro line will be constructed at Level-2, while the elevated road will be positioned at Level-1, ensuring seamless connectivity to the Kilambakkam bus terminus. Additionally, ramps near Tambaram will link commuters to the Outer Ring Road. The elevated road will directly connect to the Kilambakkam bus stand, with the potential for an extension to Chengalpattu in the future.

The proposed metro extension will pass through key suburban areas such as Pallavaram, Chrompet, Tambaram, Perungalathur, and Vandalur. The alignment will enhance connectivity between major transport hubs, including Kilambakkam bus terminus, Chennai International Airport, and Tambaram railway station, providing commuters with a more efficient transit option.

Larsen & Toubro Infrastructure Engineering conducted a feasibility study for the airport-Kilambakkam metro link in 2019. However, delays in DPR preparation resulted in CMRL submitting the initial report in early 2022. A major hurdle during this process was the state highways department’s plan to build an elevated corridor up to Tambaram, which conflicted with the proposed metro route. After extensive discussions, both agencies reached an agreement on the viaduct's level and the height of the elevated corridor.

During the feasibility study, CMRL evaluated three potential routes: a 16 km stretch along GST Road, a 19 km route extending from GST Road to Tambaram and Mudichur Road, and a 20 km alignment passing through Airport-Cantonment-Pallavaram Bus Stand, GST Road via Hastinapuram and Tambaram West, and Mudichur Road to Kilambakkam. Despite concerns over the GST road alignment’s proximity to the existing suburban rail service (Beach to Tambaram), CMRL chose this route due to its fully elevated design and minimal land acquisition requirements compared to other options.

The submission of the revised DPR marks a key step towards realising the project, which promises to improve public transport infrastructure and connectivity for Chennai's commuters. However, its implementation still depends on approval from the Union government.