Delhi Metro

The Delhi Metro is India's largest and busiest mass-rapid-transit system — a 393 km network spanning Delhi, Gurugram, Noida, Faridabad, and Ghaziabad with 288 stations across 12 colour-coded lines. Operated by Delhi Metro Rail Corporation (DMRC), the system carries approximately 6 million passenger journeys per day and is the world's 8th-largest metro by length.

DMRC was incorporated in 1995 as a 50:50 joint venture between the Government of India and the Government of Delhi. Construction began in 1998 with technical and financial assistance from the Japan International Cooperation Agency (JICA), which has provided ~60% of project funding through soft loans across all phases.

Phase I (Red, Yellow, Blue lines — 65 km) was delivered ahead of schedule and under budget by 2005, an unprecedented feat in Indian public-works execution. Phase II (75 km) added the Green, Violet, and Airport Express lines by 2011. Phase III (160 km) added the Magenta and Pink lines plus extensions by 2019. Phase IV (104 km, six new corridors) is currently under construction, targeted for 2026-28 completion.

The system is the operational benchmark for all subsequent Indian metros (Mumbai, Bengaluru, Chennai, Hyderabad, etc.). It introduced unmanned train operation (UTO) on the Magenta Line in 2018 — India's first driverless metro service.

Notable engineering: 220+ km of tunnel built using 50+ Tunnel Boring Machines; the deepest station (Hauz Khas, 29 m below ground); and a centralised Operations Control Centre at Metro Bhawan that coordinates all 12 lines.