Bengaluru's longest tunnel-like underpass to come up near Yelahanka airbase

Bengaluru: Bengaluru's longest tunnel-like underpass is set to come up near the Yelahanka Air Force Station on the airport highway. 

The National Highways Authority of India (NHAI) has invited Requests for Proposal (RFP) to build a depressed service road — an underpass constructed about six metres below the main road level — at a cost of Rs 51.27 crore, excluding GST. 

Besides the 320-metre covered depressed service road, the project includes an 800-metre surface-level road, relocation of Indian Air Force (IAF) assets and other allied works. 

The underpass will have two lanes with paved shoulders. It will connect the IAF station’s domestic area to its technical area, and also link the runway to Hunasamaranahalli Lake, said KB Jayakumar, Project Director at NHAI, Bengaluru. 

"This is the only stretch on the airport highway that does not have a service road. It is a black spot on the 22.12-km Hebbal-Trumpet section of National Highway 7 (now known as NH 44). The NHAI has given all necessary clearances for the project," Jayakumar told DH. 

According to the official, the underpass will be far longer than any existing one in the city. "It will be a tunnel-like road built using the cut-and-cover method," he noted. 

Under this method, a trench is excavated from the surface, the tunnel is built within it, and the road is restored with backfilling. 

In contrast, the 16.75-km Silk Board Junction-Hebbal tunnel road will be constructed using Tunnel Boring Machines (TBMs), which are also used for underground metro lines. 

The NHAI will shift IAF assets, including the entrance gate and the compound wall, and has already completed the work for around 200 metres, the official added. 

Bids will be opened on February 25, with the contract expected to be awarded by March-end, Jayakumar said. 

While the project deadline will be 18 months from the date of award, the NHAI aims to complete a big chunk of the work ahead of Aero India 2027, scheduled for February next year. No traffic diversions will be required during construction, he added. 

The NHAI has recently built service roads at two locations on the airport highway: a one-kilometre stretch opposite Esteem Mall in Hebbal and a 1.1-km-long stretch at Jakkur. Both roads are about 10 metres wide. 

It is also constructing a 700-metre-long, six-lane underpass at Sadahalli to remove the only signal on the airport highway. 

The Rs 35-crore project has been awarded to Vidya Infratech Pvt Ltd and work will start soon. The completion timeline will be 15 months, Jayakumar said.