Can the 'underworld' rid Mumbai of its traffic nightmares?

As the city exhausts surface options, 11 tunnel-based projects ranging from east-west corridors to rail systems like the Metro and the bullet train are expected to offer seamless connectivity across Mumbai Metropolitan Region

It was in the late 1990s that the transformation of Mumbai started with a slew of flyovers dotting the cityscape. But with the passage of time, these flyovers proved to be inadequate to cater to the rapidly increasing vehicular density in India’s financial capital.

And the limitation of horizontal expansion in the city meant that Mumbai needed more infrastructure projects. As bridges and elevated Metro corridors criss-cross the mega city today, urban planners are of the view that going underground, albeit costly, is a viable option for not only the Metro projects but also road corridors.

At present, there are at least 11 tunnel-based projects in the making, ranging from east-west corridors to rail systems like the Metro and the bullet train, across the Mumbai Metropolitan Region (MMR).

The Metro 3 corridor (Colaba-Bandra-Seepz), one of the first underground mass transit projects in Mumbai, is almost ready. India’s first undersea twin tunnels, which are a part of the Mumbai Coastal Road project, are also getting finishing touches. 

Authorities have finalised contractors for three east-west tunnel-based road corridors, floated tenders for four out the nine underpasses on the Western Express Highway (WEH) and the Eastern Express Highway (EEH) for grade separation projects. Work is also in progress on the bullet train tunnel and Metro Line 7A (Andheri-Domestic airport.)

(Only pictures for 3 projects – Coastal Road, Metro 3 and bullet train project are available currently.)

Can tunnels ease woes?

Experts feel that although late in the game, Mumbai can find a solution by laying underground mass transit corridors given it’s basically an island and there is little scope for horizontal expansion.

With a vehicular population of 45 lakh, including 13 lakh private cars, the city faces perpetual traffic chaos. The congestion often leads to long jams, pollution and wasteful fuel expenditure. For the record, Mumbai has the highest density of private cars in the country at 650 per kilometre of road.

In densely populated urban areas, tunnels can help minimise disruption by allowing trains to pass underneath, while avoiding the need for extensive land acquisition or causing disturbances on the surface.

Government officials say that going underground may be a little more expensive compared to building on top of a road, but delays caused by land acquisition, legal cases and traffic diversions can be avoided.

“London had its first underground Metro in 1863. Mumbai is at least 100 years behind, but it is a much-needed start,” says an official.

Ensuring safety & security

Experts say that apart from offering space, tunnels enhance safety by avoiding level crossings, reducing the risk of collisions with road traffic. They also offer security advantages by providing a controlled and confined space.

Tunnels allow for grade separation, meaning the road or railway can pass beneath existing transportation infrastructure like roads and highways without impeding surface traffic flow.

Tunnels in railway networks have been used for a long time because of the peculiar topography in the Sahyadri ranges. In regions with challenging topography, such as mountains, hills, or water bodies, tunnels provide a means to navigate through obstacles, allowing for a more direct and efficient rail route.

Mumbai Railway Vikas Corporation (MRVC) is digging a tunnel for extension of the Harbour line from Panvel to Karjat. So far it has excavated a tunnel over a length of 2km.

MRVC chairman and managing director SC Gupta says, “Due to the challenging topography of mountains/hills falling in alignment of the Panvel-Karjat new suburban corridor, tunnels have been strategically employed to overcome geographical challenges, minimize environmental impact, enhance safety, and optimise the efficiency of the system.”

Dhawal Ashar, head, Sustainable Cities & Transport at World Resources Institute (WRI), India, however, stresses that for a city like Mumbai, the focus should be on both seamless connectivity and last-mile access irrespective of the mode of transport.

“Underground transit in the case of Mumbai was a lot more expensive. Underground transport systems are however not constrained to run along the arterial roads, as is the case of the above-ground Metro. For Mumbai, looking ahead, the focus has to be on creating seamless first and last mile access to and from every transit node, be it the Metro or the suburban rail.

“Over the next 3-4 years, Mumbai will add public transport capacity that hasn't happened over the last two decades, in the form of over 300kms of Metro and hopefully 10,000 buses. There is now a golden opportunity to improve mobility in Mumbai, by focussing on building a seamless, well connected pedestrian infrastructure,” he says.​

Watch: What experts say on Mumbai's transport system moving underground