What do experts say about Tunnel road in Bengaluru?

Intro

After reading the post on Deccan Hearald where Kiran Mazumdar-Shaw said and I quote:

"In every city in the world, tunnels can cut the distance and create new passageways. I think it is important,”

If that is not a general definition of what tunnel is, I don't know how you can tunnel. So, I asked myself this question - What do experts say about Tunnel road in Bengaluru? Since I don't know any experts, I asked Gen AI Gemini the same question and the text I got from Gemini is what you see below.

The proposed Bengaluru tunnel road project, connecting Hebbal to Central Silk Board, is a subject of intense debate among urban planners, environmentalists, and transportation engineers. While the Karnataka government promotes it as a "global city" solution, independent experts have raised significant red flags regarding its technical, financial, and environmental viability.

1. Transportation & Mobility Concerns

A primary critique from experts is that the project promotes "induced demand"—the phenomenon where building more roads encourages more private vehicle use, eventually leading back to congestion.

• IISc Study on Underutilization: A study led by Prof. Ashish Verma of the IISc Sustainable Transportation Lab suggests the tunnel would be severely underutilized. The research found that it would fail to significantly decongest the Outer Ring Road (ORR) and could increase overall emissions by up to 18%.
• Conflict with Public Transit: Experts argue the tunnel's alignment almost exactly mirrors Namma Metro Phase 3A (Red Line), undermining the viability of mass transit systems like the Metro and suburban rail.
• Inequity in Access: Mobility activists like Rajkumar Dugar (Citizens for Citizens) emphasize that the tunnel excludes two-wheelers, three-wheelers, and buses, catering almost exclusively to a small percentage of affluent car owners.

2. Environmental & Geological Risks

The project’s path beneath some of the city’s most sensitive areas has sparked alarm:

• Threat to Lalbagh: Geologists and activists are concerned about the tunnel passing beneath the 3-billion-year-old Peninsular Gneiss rock in Lalbagh. There are fears that vibration and excavation could damage this National Geological Monument and the garden's groundwater aquifers.
• Flooding & Aquifers: Experts at the National Institute of Rock Mechanics warn that tunneling could disrupt underground water channels feeding lakes like Lalbagh and Hebbal, potentially leading to drying or contamination of local wells.

3. Financial and Governance Issues

The economic model and the transparency of the planning process have been heavily questioned:

• High Toll Costs: Estimates suggest a one-way toll could reach ₹318 to ₹330 per trip, potentially costing regular commuters up to ₹18,000 a month.
• DPR Deficiencies: A government-appointed expert committee identified over 120 technical and financial deficiencies in the Detailed Project Report (DPR). Issues include insufficient soil testing—using only four boreholes for a 16km stretch—and a lack of hydraulic analysis for stormwater.
• Data Integrity: The BBMP recently fined the project consultant ₹5 lakh after the DPR was found to have mistakenly included traffic data from cities in Maharashtra (Nashik and Malegaon) instead of Bengaluru.

4. Comparison of Perspectives - 1

Would you like me to find the latest updates on the National Green Tribunal (NGT) hearings or the Karnataka High Court's stance on the tree-cutting issue?---

5. Comparison of Perspectives - 2