The Karnataka government is reconsidering the alignment of Bengaluru’s proposed tunnel road after criticism that the project could affect Lalbagh and its underlying Peninsular Gneiss. The proposal is not yet a cancellation or a final redesign. It is an indication that the location of the tunnel’s entry and exit points, along with its ramps, may be revisited before the project advances further.
The issue was discussed at the second meeting of the Greater Bengaluru Authority, chaired by Chief Minister DK Shivakumar and Bengaluru development minister Krishna Byre Gowda. According to the report, officials were instructed to examine the advantages and disadvantages of shifting the tunnel road’s entry and exit points away from the park. Shivakumar told reporters that the government was exploring alternatives.
That distinction matters. The government has not announced a new alignment, published a revised design or stated that the project’s cost and schedule will remain unchanged. What exists at this stage is a reconsideration of a major infrastructure proposal after environmentalists and park users objected to the possible impact on Lalbagh.
The tunnel road project was earlier proposed as a 16.7-kilometre underground route with an estimated cost of Rs 16,980 crore. The government had also proposed acquiring five acres of land for the project. The report does not establish whether the proposed land acquisition would be avoided under an altered alignment, nor does it specify how much the cost, construction method or timeline could change.
Those unanswered questions are central to understanding the project. A tunnel is often presented as a way to add road capacity without using large amounts of surface land. But underground infrastructure still requires surface-level portals, ramps, ventilation or service facilities, construction staging areas and connections to the existing road network. The debate over Lalbagh therefore concerns more than the tunnel boring section itself. It concerns the points at which a buried transport system meets the city above ground.
Lalbagh occupies an unusual position in Bengaluru’s urban geography. It is a major public park, a landscape with long-standing ecological and cultural value, and a piece of open space within a heavily built-up city. The government’s concern, as reported, includes possible damage to the three-billion-year-old Peninsular Gneiss associated with the site. The significance of the proposed alignment is consequently tied to both the park’s surface environment and the geological conditions below it.
The current controversy illustrates a recurring challenge in large urban projects: alignment decisions can appear technical when they are first presented, but they distribute costs and risks across public spaces, neighbourhoods, road users and institutions. The choice of an entry or exit point determines where construction disruption is concentrated, which roads absorb traffic, which land may be acquired and which public assets face direct or indirect pressure.
In this case, the government’s willingness to explore alternatives suggests that the alignment is not being treated as immovable. It also shows that the project remains at a stage where a design decision can still be reconsidered, although the supplied information does not state the project’s exact approval, tendering or construction status. Without those details, it is not possible to determine whether a shift would be an early planning adjustment or a substantial redesign after commitments have already been made.
The institutional setting is also important. The discussion took place at a Greater Bengaluru Authority meeting rather than being described as a standalone announcement by the road project’s executing agency. The report says the meeting cleared 11 proposals, including a Rs 450 crore infrastructure development project for the Outer Ring Road and white-topping-related works. This places the tunnel road discussion within a broader programme of city infrastructure decisions, rather than treating it as an isolated engineering exercise.
However, the meeting’s approval of other proposals does not establish that the tunnel road itself received final approval. The available information only records deliberation over a possible change in alignment. It does not identify the authority responsible for the final technical decision, provide an environmental assessment, or disclose a revised route map. Those documents would be necessary to evaluate whether the alternative is genuinely less damaging or merely relocates impacts to another part of the city.
The numbers attached to the project help explain why the alignment question is consequential. A 16.7-kilometre tunnel with an estimated price of Rs 16,980 crore represents a large public infrastructure commitment. The reported cost works out to roughly Rs 1,017 crore per kilometre, although that is only a simple division of the announced project estimate and should not be read as a comparable construction benchmark. The project’s scale means that even a change limited to portals and ramps could affect design, land requirements, utilities, traffic management and expenditure.
The proposed acquisition of five acres is another important indicator. The figure is small compared with the overall length of the tunnel, but surface land requirements are not measured only by area. Location matters. Land near a tunnel portal can have greater operational importance than a larger parcel elsewhere because it determines how vehicles enter and leave the system and how construction connects with existing streets.
The reported concern over Peninsular Gneiss adds a geological dimension to the planning process. The source identifies the rock as three billion years old, but it does not provide a technical assessment of how the proposed works would affect it or whether damage is expected, possible or avoidable. That gap prevents a definitive judgment about the engineering risk. It does, however, clarify why the government is examining alternatives before treating the route as settled.
The project’s public value will ultimately depend on more than its ability to move vehicles underground. The available report does not provide traffic forecasts, projected travel-time savings, daily capacity, tolling information, financing arrangements or an implementation schedule. It therefore cannot establish whether the tunnel would resolve a defined congestion problem, how many people would benefit, or how the investment compares with other possible transport interventions.
That absence of information is especially relevant because the proposal is a road project in a city where surface mobility, public transport and land use are closely connected. An underground road can create additional capacity along one corridor, but its usefulness depends on how efficiently traffic is distributed at both ends. If portals are placed in constrained or congested areas, some of the pressure may remain at the surface. The report does not provide enough evidence to assess that network effect.
Nor does the current information establish whether avoiding Lalbagh would produce a better overall outcome. A revised route could reduce direct pressure on the park while increasing construction activity, land acquisition or traffic disruption elsewhere. That is why the next stage should be assessed through published route plans, environmental and geological studies, land requirements, cost revisions and traffic modelling when those materials become available. These are not conclusions about the alternatives; they are the evidence needed to compare them.
The Lalbagh debate consequently exposes a wider governance question. How should Bengaluru decide whether a major mobility project is compatible with the city’s limited public landscapes and geological heritage? The answer cannot rest solely on the aggregate length of a tunnel or the headline cost. It requires a clear account of where the project touches the surface, what land it needs, what risks have been assessed and which authority is accountable for revising the design.
For now, the evidence confirms three things. The government is considering moving the tunnel road’s entry and exit points and ramps away from Lalbagh; the project remains associated with a proposed 16.7-kilometre route costing Rs 16,980 crore and requiring five acres under the earlier plan; and no revised alignment has yet been publicly established in the supplied material. The next meaningful developments will be the publication of alternative designs, the government’s decision on the alignment and any resulting changes to cost, land acquisition and implementation plans.
