Anna Salai flyover redesigned at metro stations; project 62% complete

The construction of the four-lane flyover on Anna Salai in Chennai has encountered a design hurdle at points where it intersects with underground metro stations. Engineers have had to modify the original plan after discovering that the flyover's alignment did not match the pre-built structures of the metro network.

Originally, the design called for three columns at each support point, including one in the centre of the carriageway. This has now been revised to two columns placed on either side, a change that frees up space on the road below. The adjustment was necessary at station points that together span a length of 426 metres.

A senior engineer associated with the project confirmed that the redesign has received the necessary approval from the State government. Crucially, this change will not lead to any additional expenditure on the ₹612 crore project. The deviation from the original scope is approximately 7.2%, which falls within the permissible 10% limit for infrastructure works.

While the work has slowed at the station locations, it has not stopped. The rest of the flyover is being built despite challenges, including welding delays caused by gas supply disruptions. Officials report that 62% of the project is complete, with the target for finishing the remaining work set for February 2027.

The project has also involved significant utility shifting, including power cables, water and sewer mains, and telecommunication lines at 50 foundation locations. Street light poles have been relocated along the entire stretch. Of the total 132 spans planned, 42 are located at the station areas, and soil stabilisation was required at 69 points above the metro tunnels. IIT Madras is conducting third-party audits for the project.