Tunnel road vs Metro: Same alignment, varied work speeds

Underground project in tender stage, Metro stuck in approvals.

In March 2022, Karnataka announced a 36.59-km Metro line connecting Hebbal to Sarjapur, linking Bengaluru’s tech hub to the Kempegowda International Airport (KIA). 

The project, part of Phase 3A expansion, is expected to serve over 6.21 lakh passengers daily, offering interchanges with multiple metro lines. 

Nearly three years later, the state government also proposed a 16.74-km tunnel road along the same stretch to ease traffic congestion.

Unlike the metro, the tunnel road project has moved swiftly. Authorities completed the draft DPR in just three months and finalised it within the next four. Tendering began in July 2025 and is likely to conclude by year-end. 

While the tunnel road — designed for around 1 lakh vehicles a day — is racing ahead, the metro line with a much longer shelf life — remains stuck in the approval process.

The DPR of the Rs 28,405-crore project is undergoing review over its ‘steep’ cost estimates, after it was turned down by the Centre. 

Noting that the metro corridor and the tunnel road run “almost parallel to each other,” an expert committee reviewing the tunnel road had noted that the DPR did not justify how it will attract enough traffic to stay viable. 

In particular, the committee questioned the feasibility of the project, stating that the tunnel road DPR did not take into account the diversion of traffic to other competing modes of transport, including metro. 

“The general apprehension of stakeholders is that the road tunnel project on proposed alignment will become redundant. This apprehension could not be addressed in the absence of data,” the committee, led by Bangalore Metro Rail Corporation Ltd executive director S Hegaraddi, said. 

Deputy Chief Minister D K Shivakumar, who is steering the project, was apparently convinced with the idea of building the tunnel road to decongest traffic after inspecting similar projects in Mumbai.

The project eventually received the consent of the state government as it was proposed under public-private partnership even as the government would still spend about Rs 7,000 crore as its share of funding. 

16 traffic bottlenecks 

The 16.75-km tunnel road, besides connecting Silk Board and Hebbal, will have a total of 16 entry and exit ramps.

All these ramps – longer than the tunnel itself – are expected to create potential bottlenecks for tunnel users and non-users alike as they join the existing traffic junctions. 

These concerns have also been shared by the expert committee. “It is noted that efforts have been made to locate the entry/exit ramps in the vicinity of existing signal-controlled junctions to avoid traffic conflicts to the extent possible. However, the introduction of entry/ exit ramps may cause traffic congestion due to the merging of traffic emerging from the tunnel with surface traffic,” the report pointed out, suggesting improvement of roads, if required by widening them, to avoid congestions. 

Further, the committee found the DPR did not have a land acquisition plan for the 17 km of approach ramps nor estimated the actual land needed at these entry and exit points for widening of roads. 

Rajukumar Dugar, convener of Citizens for Citizens, who has analysed the tunnel road DPR, said the average length of these ramps is about 1 km. 

“So, whatever time saved on the tunnel, which could be about 10–15 minutes, will be lost in detours, U-turns and waiting at toll plazas,” he said. He felt only about 50,000 to 1 lakh car users may use the tolled-road owing to affordability. 

In his research paper, Prof Ashish Verma of the Indian Institute of Science highlighted the dangers of prioritisng private vehicle infrastructure over mass transit, while noting that no amount of car-centric solutions will address decongesting the city. 

“Tunnel roads encourage car usage, increasing congestion, pollution and environmental degradation. The project also faces flood vulnerability, lacks resilience during extreme weather and poses safety risks,” he said, urging the government to prioritize mass transit projects such as metro and suburban railway corridor. 

Cost and time overrun

As per the plan, the tunnel road costs about Rs 17,800 crore. While the government will bear 40% of the cost, a private concessionaire is required to bear the rest, which comes to Rs 11,000 crore. To attract bidders, the government has offered to charge a toll of Rs 19 per km, as well as revenue from advertising, naming rights and parking/retail spaces at intermodal hubs. It also set a four-year deadline for the project. 

However, the government-constituted committee has expressed concerns over potential time and cost overruns, citing the city’s complex geology and flood vulnerability. It said only minimal geological and geotechnical investigations were done, warning that more extensive studies are needed.

“The project schedule assumes a monthly progress of 150 metres, but metro tunneling averages only 100 metres per month, despite smaller tunnel diameters,” the committee noted. It stressed that at least 90% of the Right of Way should be cleared before awarding contracts to avoid delays. 

Satya Arikutharam, an independent consultant, criticised the project, calling it a “real estate venture disguised as infrastructure”. 

“Critical studies such as willingness-to-pay surveys, traffic feasibility assessments and cost-effectiveness analyses were not properly conducted. It is irresponsible — almost criminal — to build infrastructure primarily for cars,” he said, adding prime locations like Hebbal, Palace Grounds, Silk Board and Lalbagh are being leveraged for ancillary commercial revenue, which is clearly in bad faith.

“By proposing such commercial activity, the project will attract lakhs of new private vehicles under the pretext of decongesting surface roads,” he said.