Chennai Metro

Chennai Metro is operated by Chennai Metro Rail Limited (CMRL), a 50:50 joint venture between the Government of India and the Government of Tamil Nadu. Phase 1 — comprising the Blue Line (Washermenpet-Airport, 32 km) and Green Line (Chennai Central-St. Thomas Mount, 22 km) — opened in stages from 2015 with full Phase 1 services from 2018. JICA provided 60% of project funding through soft loans.

A distinguishing feature: 35 km of the 54 km Phase 1 is underground tunnel — Chennai's high water table, soft marine alluvium, and the requirement to traverse the Cooum and Adyar river crossings made underground alignment necessary in many sections. Civil construction was tendered in 8 packages with L&T, Afcons, Gammon India, and Skyline-CCEC sharing the work. Tunnel boring was executed by 6 EPB-shielded TBMs through marine clay and limestone.

The Egmore-Nehru Park section includes India's first 'island station' — a unique platform configuration where trains stop on opposite sides of a single platform — implemented to reduce footprint at Chennai's most constrained intersection.

Daily ridership averages 350,000 (as of 2024). The system uses Alstom-built 4-coach standard-gauge trainsets running on 25 kV AC. Phase 2 (118 km across 3 new lines) is fully under construction, with first sections targeted for 2025 opening.