The countdown has started for Delhi Metro's arrival in outer Delhi. On Friday, Delhi Metro Rail Corporation will start trials on the 4.39km extension of the Yellow line to Badli.

The extension will make commuting easier for lakhs of people living in areas like Badli, GT Karnal Road and Transport Nagar who otherwise had to change multiple rides to get to the heart of the capital.

"Construction of this elevated 4.3km stretch is almost complete and it will be opened to public after successful trials and mandatory approvals", said a Delhi Metro Rail Corporation spokesman. The extension on the corridor (HUDA City Centre-Jahangirpuri) will have stations at Badli Mor, Rohini Sector-18 and Samaypur Badli. With this stretch, the total length of the corridor will increase to 49km.

The Jahangirpuri-Badli corridor is also crucial because one station—Badli Mor—is expected to become an interchange station on phase-IV of the Metro network. It will be made an interchange link with the proposed R K Ashram- Mukundpur-Janakpuri (West) section which will connect Yellow line with line 7 (Mukundpur-Yamuna Vihar) and line 8 (Janakpuri West-Botanical Garden) that are being constructed as part of phase-III. However, the corridor is yet to be approved by Delhi government.

"The foundations and structures of the station have been designed in such a way that they will be able to take the load of the two platforms catering to phase-III and phase-IV," said a senior DMRC official.

Interestingly, the Jahangirpuri-Badli line is also one of the few Metro corridors going over a railway line in Delhi. To span the Northern Railway tracks of the Delhi-Ambala route, Delhi Metro has constructed a special steel bridge. It has also constructed two separate elevated tracks for this corridor—for the "up" and "down" lines. DMRC has crossed the railway tracks by constructing a 45m-span steel bridge on both lines.

Once trial runs on this extension of the Yellow line are successful, Delhi Metro will apply for the necessary clearance from the Commissioner of Metro Rail Safety (CMRS) before opening the line for commercial use.