According to the sources, instead of the previous design of three entries and three exits, it will now have seven entries and six exits. The six-lane flyover can cost between Rs 5,000 crore to Rs 5,500 crore.

Out of its 20.6 km stretch, 14 km will be two tiers from Napier bridge to Koyambedu. The lowest of the tier is for local traffic, and the upper for the vehicles travelling directly to Chennai Port.

As per NHAI's official, it has started preparing a detailed project report (DPR) on the alignment of the project and trying to get the Coastal Regulatory Zone (CRZ) clearance from the environmental department.

At NHAI's request, the Tamil Nadu government has approved reimbursing the royalty for the raw materials, including earth and gravel, for road projects.

NHAI would sign a Memorandum of Understanding (MoU) with the Tamil Nadu state government to commence the project, an official said. NHAI has also agreed to the proposals and suggestions given by the state government.

The government wants a connecting link to the expressway at Chintadripet, Montieth road, Binny road, Spurtank road, and near the K3 police station. NHAI has agreed to it in principle and has redirected it to the technical department to study the feasibility.

As per the original plan of the project, six ramps were planned to be built at Kamarajar Salai, Sivananda Salai, College road, Spurtank road, and Arumbakkam.

According to the officials, since the state government agreed on it in principle to expedite the project, NHAI would begin the construction work by 2022, and the bids will be invited by September end.

The technical department is also studying the stability of the pillars along with the alignment of the project.