Cochin International Airport (CIAL) and Kochi Metro Rail (KMRL) are expected to collaborate on the construction of the proposed underground metro rail line and station at Nedumbassery. KMRL plans to develop a 3 km underground metro line at Nedumbassery, which will feature an underground station connected to the airport as part of its proposed Phase-III, aimed at linking Aluva with Angamaly.

The proposed underground station is designed to be similar to the Delhi Metro's Airport Express Line or the Orange Line from New Delhi to Yashobhoomi Dwarka Sector-25, which connects to Indira Gandhi International Airport. Given the significant costs associated with building underground rail lines and stations, KMRL has requested CIAL's collaboration on the project. Ongoing discussions between KMRL officials and CIAL stakeholders have yielded positive developments, according to sources.

According to the proposed Phase-III project by Kochi Metro, the extension line will begin at Aluva and follow National Highway-544 until it reaches Aleena Valavu near Akaparambu. The route will then proceed along the Kariyad-Airport-Mattoor road to Nedumbassery International Airport. From there, it will continue on the Angamaly-Airport road to MC Road, extending along MC Road until Angamaly. From the junction on MC Road at Angamaly, the metro line will head towards Thrissur, extending approximately 2 km on NH-544.

A senior KMRL official noted that the total construction cost for the Phase-III line is estimated to be around Rs 80 billion. While the construction of the underground line is costly, they anticipate that CIAL will contribute approximately Rs 10 billion towards the construction of the underground structures, with the state government acting as the implementing agency. KMRL has submitted the project proposal for the Phase-III extension of Kochi Metro to the Union Ministry of Housing and Urban Affairs (MOHUA), and final approval is expected soon.