Chennai's highways department has completed around 70 per cent of the four-lane three point two kilometre elevated corridor on Anna Salai and plans to open it by end of November. The project is the country's first elevated corridor built directly above an operational metro tunnel and is assembled from prefabricated steel components. Engineering complexity has increased costs to Rs 6.21 billion (bn), making it costlier than a conventional highway project.

The corridor is expected to cut travel time between Teynampet and Saidapet from about 30 minutes to just five minutes and to ease congestion at seven major intersections. Officials say about one point nine kilometre has been completed and 46 of the 69 piers have been erected. The metro tunnel runs 14 to 15 metres below Anna Salai, so foundation drilling was limited to seven metres from the road surface.

Of the three point two kilometre stretch, about two point four kilometre passes above the metro, including a 460 metre section over Teynampet and Nandanam stations, while 655 metres lies off the metro alignment. Reinforced concrete deck slabs cover approximately two kilometre of the corridor and 41 portal frames are being installed above the stations. Completion was originally scheduled for September but slowed after workers returned home during the April elections and resumed work later.

Nighttime permissions restrict on-site work to six hours, but officials report activity has gathered pace and completion is expected by end of November. Around 15,000 t of prefabricated steel components are being manufactured in Gujarat and Telangana and transported to Chennai, while RCC deck segments of about 15 metres are placed over the girders. A commuter from T Nagar noted that traffic diversions from the flyover and metro works have caused severe congestion and urged the highways department to expedite remaining work.