Adani Enterprises’ lowest financial bid of ₹22,267 crore for Bengaluru’s 16.75-km twin tunnel road project is 95.77% higher than its original planning benchmark. Overshooting the state's revised estimates by ₹4,569 crore, the massive cost increase has pushed the landmark project into a strict cabinet review over potential toll risks.
BENGALURU — Internal documents reviewed on Wednesday, June 24, 2026, reveal that Adani Enterprises Limited’s financial bid for the proposed Bengaluru North–South tunnel road project is up to 95.77% higher than the original cost benchmark established during preliminary planning phases. While the infrastructure conglomerate is the lowest bidder for the underground corridor, the sharp increase from early government baselines has intensified political and fiscal scrutiny inside the Karnataka administration as the contract awaits a final cabinet decision.
Discrepancies Between Original Planning and Revised Tenders
The project, spearheaded by the special purpose vehicle Bengaluru Smart Infrastructure Limited (B-SMILE), aims to build a 16.75-kilometer twin-tube underground passage running between Hebbal and the Central Silk Board junction. Initial internal estimates calculated during early desk studies valued the massive engineering effort at a significantly lower baseline. However, as the technical scope evolved to account for structural demands, the state government formally adjusted its official tender projection to ₹17,698 crore ($176.98\text{ billion}$).
When the financial bids were unsealed, Adani Enterprises emerged as the lowest bidder (L1) with a combined quote of ₹22,267 crore for the two main packages. Although initial public perceptions framed this as a 24% to 28% increase over the government's revised tender limits, internal documents show that the finalized bid is nearly 96% above the original planning benchmark, prompting deeper administrative reviews regarding long-term cost controls.
Geological Realities and Structural Scope Revisions
Engineering experts note that the vast difference between early benchmarks and actual commercial bids stems from the complex geological realities of drilling underneath high-density urban areas. Bengaluru's underground landscape contains hard granitic rock formations and complex soil variations that require highly specialized Tunnel Boring Machines (TBMs) and heavy reinforcement.
Furthermore, early detailed project reports lacked extensive geotechnical data. In mid-May, Adani Enterprises began initial on-ground surveys and soil testing along the Hebbal–Silk Board corridor to refine its engineering blueprints. The finalized plans divide the project into two distinct operational packages:
Package 1: Covers the northern stretch connecting Esteem Mall at Hebbal to the Seshadri Road–Race Course junction, where the bid overshot official estimates by roughly 24%.
Package 2: Spans from Seshadri Road to the busy Central Silk Board junction, recording an escalation of nearly 28% above government expectations.
Political Implications and Financial Fallout for Commuters
The contract approval faces a complex political climate in Karnataka. Deputy Chief Minister and Bengaluru Development Minister D.K. Shivakumar continues to champion the twin-tunnel road as an essential solution to bypass over 25 major traffic bottlenecks and cut down daily commute times by up to 45 minutes.
However, opposition party members and local civic groups have raised concerns regarding the financial model. The project is planned under a Build-Operate-Transfer (BOT) framework, with the Karnataka government funding 40% of the cost and the private developer covering the remainder. Because the final bid came in ₹4,569 crore above the government’s ceiling, critics warn that private operators may enforce higher toll rates on local four-wheelers over the proposed 34-year concession period to recover the expanded capital investment.
Official Sources Section
The financial figures, package breakdowns, and procurement timelines cited are based on internal evaluation logs from Bengaluru Smart Infrastructure Limited (B-SMILE) and statutory infrastructure filings reviewed by the Government of Karnataka and state urban development bureaus.
Quote Section
"According to officials familiar with the internal documentation, the negotiated pricing structure reflects heightened contingency costs designed to offset unforeseen geological risks when drilling below built-up metro corridors."
"Organizers stated that while the commercial quotes significantly exceed early planning estimates, the high-precision nature of the 16.75-km twin-tube corridor makes the use of advanced underground engineering essential."
Why It Matters
The outcome of this bidding dispute will heavily influence future large-scale public-private partnerships in India. Accepting a bid that sits 96% above original project benchmarks could establish a precedent that drives up capital demands for major urban infrastructure projects, directly impacting municipal budgets and the toll structures paid by urban travelers.
Key Facts at a Glance
The Bid: Adani Enterprises is the lowest bidder for Bengaluru's tunnel road at ₹22,267 crore, overshooting revised estimates by ₹4,569 crore.
The Variance: The final bid is 24% to 28% higher than the revised government estimate, but sits 95.77% above the original planning benchmark.
The Infrastructure: The plan features a 16.75-kilometer twin-tube underground route aimed at connecting Hebbal to the Silk Board junction.
Financial Model: Designed as a Build-Operate-Transfer (BOT) initiative, where the state covers 40% of the construction costs.
Current Status: The contract file has been escalated and is currently pending a final decision by the Karnataka state cabinet.
FAQ Section
Why is the Adani Group's bid for the Bengaluru tunnel road so much higher than original numbers? The price adjustment accounts for complex underground granitic rock formations, the need for advanced Tunnel Boring Machines, and extensive adjustments made after the project's initial planning scope was expanded.
How will this cost escalation affect everyday commuters in Bengaluru? Because the project relies on a public-private partnership model where the developer covers 60% of funding, the ₹4,569 crore cost overrun could lead to higher toll rates for private vehicles using the tunnel.
Has the contract been officially awarded to Adani Enterprises? No. While Adani Enterprises is the validated lowest (L1) bidder, the cost escalation beyond the approved ceiling requires formal approval from the Karnataka state cabinet before construction can begin.
Source: Deccan Herald, The Hindu, The News Minute
