The ‘Missing Link’ on the Mumbai-Pune Expressway has a new claim to fame. The twin tunnels that are part of the recently opened Missing Link project have been recognised by Guinness World Records as the widest underground tunnels in the world.
One of the twin tunnels on Mumbai-Pune ‘Missing link’ widest in the world
Each tunnel is 22.33 metres wide and accommodates five lanes of traffic. This width, combined with the engineering required to build them through difficult terrain, sets them apart from similar infrastructure projects globally.
Speaking to Financialexpress.com on the world record, Anilkumar Gaikwad, Vice Chairman and Managing Director of the Maharashtra State Road Development Corporation (MSRDC), said, “This recognition is a matter of immense pride for MSRDC and the state of Maharashtra. One of the twin tunnels (T2) of the recently opened Connecting Link (Missing Link) project has been certified by the Guinness World Records as the world’s widest tunnel, with a width of 22.33 metres. This engineering milestone on the Mumbai–Pune Expressway reflects our commitment to delivering world-class infrastructure that enhances safety, efficiency, and travel experience.”
What makes these tunnels special
According to PTI, the tunnels were built to bypass the congested Khandala Ghats section, which has long been a bottleneck for traffic between Mumbai and Pune.
The project was inaugurated on Maharashtra Day by Chief Minister Devendra Fadnavis, along with Deputy Chief Ministers Eknath Shinde and Sunetra Pawar. Navayuga Engineering Company is one of the companies associated with Maharashtra State Road Development Corporation for the construction of the Missing Link.
According to Chinta Sridhar, Managing Director of Navayuga Engineering, the project represents more than just a world record. “This is a statement of what India can build,” he said. “Delivering the widest underground tunnel through the challenging basalt terrain of the Sahyadris reflects our ability to execute complex, design-led infrastructure at a global scale.”
The challenge of building through mountains
Constructing the tunnels required cutting through the Sahyadri mountain range, known for its hard basalt rock, the PTI report added. The project involved excavating over 8.5 million tonnes of rock using controlled blasting techniques, as per PTI. The blasting had to be carefully managed to avoid damaging the existing expressway that runs nearby.
Ramesh Singooru, Senior Vice President of Navayuga Engineering, explained that the project faced several difficult conditions. “The project presented formidable execution challenges, particularly due to complex land constraints and the steep gradients of the hilly and valley terrain,” he told PTI.
To address these issues, engineers created access tunnels, installed cross passages every 300 metres, and used advanced tunnelling methods. One particularly tricky section involved construction beneath a large water body, which required extra safety measures and monitoring systems, the PTI report said.
The numbers behind the project
Workers used 7,600 tonnes of steel to reinforce the tunnel structure. Over 110,000 cubic metres of concrete went into shotcrete for structural stability, while another 220,000 cubic metres were used for pavement-quality concrete to ensure the road surface would last.
The project took 9 million work hours to complete. Part of the work included building viaduct structures across a valley nearly 180 metres wide, using specialised girders designed for challenging terrain, as per the PTI report.
Safety systems inside
The tunnels are equipped with modern safety technology. A SCADA system monitors the entire corridor around the clock, tracking traffic flow, air quality, and tunnel operations in real time. Artificial intelligence helps manage the monitoring and control systems.
Cameras are positioned every 150 to 300 metres throughout the tunnels. Automatic number plate recognition systems are installed at entry and exit points for security and traffic management, the PTI report said.
Air quality is maintained through jet fan ventilation systems that constantly monitor carbon monoxide and nitrogen oxide levels.
For fire safety, the tunnels have automated detection systems and high-pressure water mist suppression equipment. Firefighting cross passages are located every 300 metres for quick evacuation if needed.
Emergency assistance is accessible throughout the tunnels. The PTI report further added that SOS systems are placed every 150 metres, with emergency push buttons every 50 metres. An FM radio system can broadcast emergency alerts to drivers, and a public address system connected to the central control room allows direct communication with tunnel users, as per the report.