Rs 7,000-crore Mumbai-Pune Expressway section crumbled in just 9 weeks

The new alignment shortened the journey by nearly 6 km, reducing travel time between Mumbai and Pune by 20 to 30 minutes, with a speed limit of up to 100 kmph.

Why was it considered an engineering marvel?
Spread across 13.3 km, the Missing Link comprises two twin tunnels measuring 1.6 km and 8.9 km, two high-speed viaducts and a 183-metre cable-stayed bridge soaring above Tiger Valley, making it the tallest bridge of its kind in the country.

Commuters walk along waterlogged railway tracks in Virar amid heavy monsoon rains that disrupted suburban train services across Mumbai. (Express Photo by Akash Patil)

The 8.9-km main tunnel, excavated nearly 180 metres below Lonavala Lake using the New Austrian Tunnelling Method, is among the widest road tunnels in the world. Engineers also had to construct temporary access passages through the Sahyadri hills. Designed to withstand the region’s high winds, dense fog, and intense monsoon rainfall, the project took nearly three decades to materialise.

Why did it take so long?
The need for an alternative to the accident-prone ghat section was first identified by RITES in 1995, even before the Mumbai-Pune Expressway was built.

The Maharashtra Cabinet approved the project in 2017, construction began in 2019 and was subsequently delayed by the Covid-19 pandemic, difficult geological conditions and the engineering challenges of tunnelling through the Western Ghats.

At its inauguration on May 1, Fadnavis described the Missing Link as Maharashtra’s new “connecting link”, while the Maharashtra State Road Development Corporation (MSRDC) projected it as a permanent solution to congestion and accidents on the ghat section. MSRDC Managing Director Anilkumar Gaikwad had said the project would make travel between Mumbai and Pune “quicker and more reliable” by eliminating one of the busiest chokepoints on the expressway.

What happened on Monday?
The Missing Link suffered its first major disruption barely nine weeks after it was opened to traffic, after a landslide and damage to a retaining wall forced authorities to suspend vehicular movement through the stretch. The landslide resulted in a heavy flow of water on the Pune-to-Mumbai carriageway.

According to the State Highway Police, the incident occurred in the early hours of Monday following continuous heavy rainfall. Officials said a landslide took place near the end of the first tunnel on the Pune-to-Mumbai carriageway of the Missing Link, damaging a retaining wall and rendering the route unsafe for traffic.

The Pune-to-Mumbai carriageway was immediately closed. Authorities initially suspended traffic in both directions, but around 10 am reopened the Mumbai-to-Pune carriageway while the Pune-to-Mumbai corridor remained shut. Since both the Missing Link and the adjoining flyover remained closed for Mumbai-bound traffic, vehicles travelling from Pune were diverted through the old Mumbai-Pune Highway (NH-48), with traffic being restored in phases.

A waterlogged stretch on Narangi Bypass Road in Virar West following heavy monsoon rains (Express photos by Akash Patil)

The disruption came at a time when the old Pune-Mumbai Highway was also shut after a tree collapsed onto a power line, while heavy rainfall led to water accumulation at several locations. With both routes affected simultaneously, authorities appealed to motorists to postpone travel between Pune and Mumbai and follow official traffic advisories.

The closure comes barely nine weeks after the project’s inauguration, when it was showcased as the biggest upgrade to the region’s infrastructure since the country’s first access-controlled expressway opened in 2002.

Its closure after the landslide is the first major disruption on the corridor during the monsoon. It also underlines the challenge of building transport infrastructure through the Sahyadris, where heavy rainfall and unstable slopes continue to test even the state’s most ambitious engineering projects. Ironically, the road conceived to free motorists from monsoon disruptions on the old ghat section ended up sending them back to that very route within its first rainy season.

What did the road authority say?

The Maharashtra State Road Development Corporation (MSRDC) has blamed the incident on nature, describing it as an “act of God”. The road authority also stressed that mitigation measures and designs were in place to counteract the landslides, but only to an extent. “This is not the contractor’s fault; it is nature at play,” said Anilkumar Gaikwad, vice chairman, MSRDC.

Gaikwad said that some boulders slid from the top due to relentless rain, blocking the mouth of tunnel 2. He said, “The tunnel structure has not been affected, but the false frame – which is an external structure built at the edges of tunnels – has been damaged.”

Another MSRDC official added that “rock fall mitigation measures are in place, vetted by IIT-Bombay. This includes rock boulting mesh up to a height of 15 meters on the mountain over the tunnel. That is still intact. But the boulders falling down are coming from a height of around 150m. Such heavy rainfall is akin to an act of God, with little that can be done to prevent it.”

Defending the work carried out on the project, the corporation said the tunnel had not suffered any structural damage.