Bengaluru Gets Green Light For 12,690 Crore Twin-Tube Tunnel And Rs 500 Crore Sky Deck Projects

The Karnataka Cabinet has granted in-principle administrative approval for ambitious infrastructure projects in Bengaluru, including the construction of a tunnel road, and a skydeck.

The 18.5 km twin-tube tunnel road project connects Hebbal flyover (Esteem Mall) to Silk Board Junction. The project, with an estimated cost of Rs 12,690 crore, aims to alleviate traffic congestion in the city.

The decision follows a feasibility study by Altinac Consulting Engineering Inc., which recommended a single-tube tunnel as a cost-effective option, although the cabinet opted for the twin-tube model in line with Indian Road Congress norms and similar projects in Mumbai.

The project will be executed under the build, operate, and transfer (BOT) model, with the possibility of being implemented as a toll road under a public-private partnership (PPP) framework. The State government has agreed to provide 40 per cent Viability Gap Funding (VAF).

If no bidders emerge for the BOT model after two tenders, the project may be undertaken by the government under the Hybrid Annuity Model (HAM) through the Engineering Procurement Contract (EPC) method, with toll revenue collection retained by the government.

In addition to the tunnel road, the cabinet also approved the construction of a skydeck, estimated to cost Rs 500 crore.

The skydeck proposal has been developed by the design and architecture firm Coop Himmelb(l)au from Austria, in collaboration with the World Design Organisation (WDO) in Bengaluru.

The design of the skydeck is said to have drawn inspiration from the intricate algorithms that govern the natural growth of the banyan tree, including its sprawling branches, hanging roots, and blooming flowers.

The 250-metre-tall structure will be divided into three parts — base, trunk, and blossom — and aims to provide visitors with a sense of being immersed in nature.

Once completed, the structure will offer visitors various entertainment and recreational facilities. The base section will house amenities such as a shopping passage, restaurants, a theatre, and a sky garden. The top portion will feature a rollercoaster station, an exhibition hall, a sky lobby, a skydeck for panoramic views, a restaurant and bar, and a VIP area.