# IISc study warns Hebbal tunnel may only shift congestion 2026-08-27T05:55:48+00:00 | Governance | Indian Opinion Desk Corroboration: 1 independent outlet A traffic impact study by the Indian Institute of Science (IISc) has warned that Bengaluru's proposed 2.2-km tunnel between Hebbal flyover and Veterinary College risks severe congestion at entry and exit points, flooding near Hebbal Lake, and cost overruns. The six-lane cut-and-cover tunnel would cost Rs 5.23 per passenger against Rs 0.86 for an underground Metro alternative, the study found. Prepared by the IISc Sustainable Transportation Lab, the study assessed 2027, 2031 and 2041 scenarios. It predicts new bottlenecks near Esteem Mall and Veterinary College, with a sharp 60-metre curve at the Esteem Mall exit dropping speeds from 60 kmph to 40 kmph. The report also flags discrepancies in the tunnel's Detailed Project Report, alleging use of lower-than-standard road capacities and arbitrary traffic diversion estimates between 50 and 80 per cent. The study warns the low-lying location near Hebbal Lake may face flooding risks, and the DPR does not address flood scenarios or evacuation plans. It recommends prioritising mass rapid transit systems for sustained congestion reduction and lower emissions. The state cabinet must approve the revised cost estimate before tenders can be invited. ## Indian Opinion Analysis The tunnel is part of a broader battle over Bengaluru's mobility priorities, where road widening and grade separators compete with mass transit expansion for limited public funds. Karnataka's urban transport agency BMRCL has already received central approval for the Phase-2B Metro corridor from Hebbal to Kempapura, which partly overlaps the tunnel route. The IISc study applies standard Indo-HCM (Highway Capacity Manual) methodology developed by the Indian Roads Congress, the same toolkit used in most DPRs. The real decision now rests with the state cabinet, which must approve the tunnel's revised cost estimate before the Bengaluru Development Authority can invite tenders. The contrast is stark: the same passenger movement costs the exchequer six times more by tunnel than by Metro, a ratio that finance department scrutiny will likely amplify. ## Coverage - newindianexpress.com Leads with study's critique of tunnel viability against Metro, flags cost comparison and DPR discrepancies without government rebuttal This brief was synthesised by AI from the source linked above. Tags: Ashish Verma, Bengaluru, BMRCL, Hebbal tunnel, Indian Institute of Science, Karnataka government Canonical: https://indianopinion.org/iisc-study-warns-hebbal-tunnel-may-only-shift-congestion/ License: Summary and commentary (c) Indian Opinion, reusable with attribution. Facts belong to the linked sources. Cite: https://indianopinion.org/iisc-study-warns-hebbal-tunnel-may-only-shift-congestion/#story-in-brief Review state: restored archive article, accurate at time of publication, not offered to search indexes. How this brief was made: an AI model read the report linked above and wrote this summary and analysis, which were published automatically. Published briefs are sampled every hour by an automated quality check; the editor verifies its findings and approves corrections, and corrected briefs carry a dated correction line. We do no original reporting. Methodology: https://indianopinion.org/ai-use-policy/