The Delhi Metro Rail Corporation (DMRC) has faced a setback in the expansion of Delhi's Metro network as it has revised the deadlines for three corridors in Phase-IV. The Phase-IV expansion aims to add 65.20 km of new lines and 46 metro stations to the national capital, with 28 km underground and the rest elevated. As part of this expansion, there will be 11 new interchange stations. The corridors included in Phase-IV are the Janakpuri West-RK Ashram Marg (29.04 km), Majlis Park-Maujpur (12.55 km), and Tughalakabad-Aerocity (23.62 km). The Janakpuri West-RK Ashram Marg and Majlis Park-Maujpur are extensions of the existing Magenta Line and Pink Line, respectively. The Tughalakabad-Aerocity corridor, known as the 'Silver Line,' connects the operational Violet Line and Airport Line from their respective ends. According to the DMRC, the Janakpuri West-RK Ashram Marg corridor, spanning 29 km, will only be operational by March 2026, which is a delay from its initial deadline of September 2025. Similarly, the Majlis Park-Maujpur corridor is expected to be completed by March 2025 instead of the previous deadline of November 2024. The Tughlakabad-Aerocity corridor is also likely to be completed by March 2026, as opposed to the earlier deadline of September 2025. In December 2018, the Delhi government approved six metro corridors, totaling 103.9 km, for Phase IV expansion. Among these, the Aerocity-Tughlakabad, Majlis Park-Maujpur, and Janakpuri West-RK Ashram corridors were categorised as priority corridors and received approval from the Union Cabinet in March 2019. However, the commencement of work on Phase IV was affected by the outbreak of the COVID-19 pandemic in March 2020. Several corridors were proposed but not approved, including Rithala-Narela (21.73 km), Inderlok-Indraprastha (12.57 km), and Lajpat Nagar-Saket G-Block (7.96 km). These corridors aimed to provide last-mile connectivity to residents. In December 2022, the DMRC took a significant step towards operationalizing Phase IV by signing a contract with Alstom Transport India for procuring 312 Metro coaches (52 trains). Out of these, 234 standard gauge coaches will be procured for the Majlis Park-Maujpur and Janakpuri West-RK Ashram Marg corridors, while 78 standard gauge coaches will be acquired for the Tughlakabad-Delhi Aerocity corridor. These trains will be compatible with driverless operations and will be manufactured at Alstom India's facility in SriCity near Chennai. The Janakpuri West-RK Ashram Marg extension will receive 144 new coaches (24 trains), the Mukundpur-Maujpur extension of the Pink Line will have 90 new coaches (15 trains), and the Aerocity-Tughlakabad Silver Line will be equipped with 78 new coaches (13 trains). Also read: Gurugram Metro Network Set to Begin Construction Hyderabad Metro Expands with Airport Metro Express Phase