Can DK Shivakumar's 'Tunnelling Under Bengaluru' Idea Work?

On 5 October, Karnataka's Deputy Chief Minister, D K Shivakumar, announced a plan to alleviate traffic congestion in Bengaluru with the construction of a 190 km long tunnel.

For years, Bengaluru has been plagued by its notorious traffic problems, prompting authorities to explore various solutions.

Now, the new regime in Karnataka has fixed its attention to create an underground tunnel road network across the city’s length and breadth.

As per the report, within the next 45 days, the state government intends to invite public tenders for this ambitious project.

Deputy Chief Minister DK Shivakumar has also sought a feasibility study on construction of tunnel roads, which he believes will be a possible solution to address the traffic gridlocks in the city.

Cost Concerns for the Tunnel Vision

The Deputy CM stated that due to the substantial scale and funding requirements of the project, it will be executed in multiple stages.

As per the earlier plans of the state government, under Phase-1, the tunnel roads had been planned over a span of 50 Km. The 50 km roads in phase-1 were estimated to cost approximately Rs 22,000 crore — at Rs 450 crore per kilometre.

The overall cost is yet to be estimated although some say it could be upwards of Rs 50,000 crore, reports Times of India.

According to a report in Deccan Herald, from a geological perspective, the city is situated on a solid and stable rock formation.

However, excavating tunnels in Bengaluru, where the rock is composed of dense granite, is a costly, challenging, and time-consuming task.  

Previously, plans to build tunnel roads in the city have been abandoned due to cost concerns and adverse feasibility reports which concluded that it was unviable.

Nonetheless, the new government in the State is mooting this option for Bengaluru.

The challenges

Critics allege that the proposal overlooks its inherent challenges and the alternate, long-term sustainable mobility solutions.

Several reports highlight the scepticism of mobility experts who question the state government's emphasis on such time- and capital-intensive projects, suggesting that such ideas lack a sustainable and efficient perspective.

Inspired From Singapore’s Mobility Plan

The proposed tunnel network takes inspiration from Singapore, which has also prompted the government to plan a visit to study its implementation.

However, as per experts, Singapore does not have an extensive tunnel-based road network.

While Singapore had conceptualised the Singapore Underground Road System (SURS) in the late 1980s, the plans for a 30km underground road network were eventually abandoned after more than 20 years.

The city has shifted its focus towards a car-lite society, prioritising enhancements to the public transport network and changes in land use policies.

Over the years, the Singapore Land Transport Authority (SLTU) has instead concentrated on improving the metro network, which has become the primary mode of transport, catering to a daily passenger load of 25 to 35 lakh.  

As per a Deccan Herald report, Sandeep Anirudhan, president of Citizens' Agenda for Bengaluru, urged the Deputy CM to learn from Singapore.

However, in Singapore, the initiatives which have strengthened public transport have also disincentivised ownership of cars and have led to a majority of people relying on public transportation.

Long Road Tunnels Primarily Cater To Car Owners

While it is possible that the idea of tunnelling may be less disruptive and holds promise of freeing land space for pedestrianising, cycle tracks, the long execution time and expense for a car-centric development makes it a wary proposition.

Building long tunnel roads in densely populated area like Bengaluru is an expensive endeavour, involving extensive engineering, and would involve developing and maintaining significant amounts of land and infrastructure, which may not be readily available.

Moreover, long road tunnels primarily cater to car owners and may exclude a significant portion of the population who rely on public transport.

Expanding car-centric road infrastructure can also lead to further urban sprawl and encroachment on green spaces.

In contrast, investing in public transport utilises existing road networks more efficiently.

While a city-wide tunnel tends to enhance the flow of traffic within the city, the ease in travelling is also believed to increase more usage of private vehicles on city roads.

Misplaced Priorities Towards an Efficient Mobility System?

The tunnel project should only be considered as a last resort after exploring and implementing all available mass transit options.

Cities like Bengaluru have complex and dense urban environments, and constructing long tunnels may not always be the most practical solution to address transportation challenges — as, such infrastructure will inadvertently prioritise private transportation, especially if it is developed before establishing an efficient public transport system.

By prioritising the efforts towards mass public transport, Bengaluru can encourage a modal shift towards more sustainable and practical solutions.

This includes focusing on expanding bus networks, speedy approvals and execution of proposed metro systems and swift implementation of suburban rail projects.

A Bangalore Mirror report suggests that comparing the existing and proposed commute modes in Bengaluru makes a strong case against the tunnel project.  

The 100 km metro track project by Bangalore Metro Rail Corporation (BMRCL) is estimated to cost Rs 50,000 crore, while the proposed 140 km suburban rail stretch is projected at a total cost of Rs 16,000 crore.

These modes of transportation have the capacity to accommodate a larger number of people using fewer vehicles, ultimately reducing overall congestion.

Experts argue that while tunnel roads only cater to car users, nearly 50 per cent of Bengaluru’s population relies on public transport such as buses and the metro.

However, the Bangalore Metropolitan Transport Corporation (BMTC) fleet of buses did not expand as required for the demand. While the number of buses in 2011-2012 was 6,064, it has only increased to 6,763 in about eight years.

Meanwhile, with the increase in the size of the city, there has been an exponential rise in the number of vehicles. In the last one decade, it jumped from 50.33 lakh in 2011-2012 to 1.04 crore till March 2022.

Changing The Vision For Integrated Road Network

The practical solutions to Bengaluru's traffic woes also include having an integrated network of shorter underpasses, elevated corridors and surface roads.

Taking the example of Singapore itself, while enhancing its public transport system, the city authorities have proposed solutions which have similar integration with multimodal access. In other words, they did not rely only on tunnelling throughout the city of such dense population.

The North-South Corridor (NSC) is a multi-modal transportation corridor that aims enhance to connectivity and relieve traffic along Singapore’s north-south transportation axis.

The project was reimagined to become the NSC in 2016 and now comprises the NSC Expressway (Viaduct and Tunnel) and the NSC ground-level streets.

The future of transportation for cities like Bengaluru are likely to involve a shift towards shared mobility, electric vehicles, and smart transportation systems.

Long road tunnels designed primarily for private cars and may become less relevant as transportation technologies evolve.