Maharashtra Chief Minister Devendra Fadnavis on December 3 inaugurated the Tunnel Boring Machine (TBM) for the state’s ambitious 9.23-km underground road corridor project connecting Orange Gate on the Eastern Freeway to Marine Drive. The launch represents a major step toward boosting Mumbai’s east–west road network and easing traffic movement across key areas of the city. Deputy Chief Minister Eknath Shinde, Assembly Speaker Rahul Narwekar, and other senior dignitaries were also present during the ceremony. With the TBM now operational, the tunnelling phase of the infrastructure development work has officially begun, marking a significant milestone for the project’s progress.
Estimated to cost approximately ₹8,056 crore, the corridor is expected to be completed in about 54 months. The project includes nearly 10 kilometres of roadway development, out of which around seven kilometres will be constructed underground. Once completed, the corridor is projected to cut travel time between Mumbai’s southern and eastern zones by nearly 15 to 20 minutes. Officials stated that the initiative will help reduce air and noise pollution by easing congestion in traffic-heavy locations. The move is expected to provide smoother travel, reduce fuel consumption, and contribute to an overall improved urban commuting experience.
According to engineering teams, the tunnel is unique in India because of its depth, alignment, and the densely populated regions it passes beneath. The route will run under critical rail transport lines, including the Central Railway, Western Railway, and Mumbai Metro Line 3. At its deepest point, the tunnel will reach nearly 50 metres underground, with an average depth between 12 and 52 metres throughout its alignment. Authorities also highlighted that this engineering undertaking involves complex planning and advanced machinery due to the challenging topography and high-density urban infrastructure above the tunnel.
The project includes dual tunnels, each designed with two 3.2-metre-wide traffic lanes and a separate 2.5-metre emergency lane. Vehicles will be allowed to travel at a maximum permitted speed of up to 80 kmph. To ensure commuter safety, cross-passages will be available every 300 metres, enabling swift emergency access when required. Additionally, the corridor will feature modern ventilation systems, fire-resistant materials, intelligent illumination, and an advanced Intelligent Transport System (ITS) designed for real-time monitoring, traffic management, and safety responses throughout the operational duration of the tunnel.
Officials said choosing an underground alignment was essential to avoid major land acquisition and minimise disruption to daily life and infrastructure on the surface. The corridor will eventually connect to Mumbai’s major transport projects, including the Coastal Road and the Atal Setu, improving last-mile connectivity and strengthening the city’s road network. Once functional, the project is expected to complement ongoing mobility initiatives and create an integrated transportation ecosystem supporting smoother logistics, faster movement, and improved accessibility across key residential and commercial zones in Mumbai.
The tunnelling work will be completed using a slurry-shield TBM, a technique well suited for Mumbai’s coastal soil conditions and previously deployed in the Mumbai Coastal Road Project. The machine being used has been refurbished under original manufacturer supervision and includes a 12.19-metre cutter head. The TBM measures nearly 82 metres in length and weighs around 2,400 tonnes. Engineers noted that the machine’s advanced configuration will help maintain safety, precision, and speed throughout the excavation process. The TBM launch officially signals the beginning of the full-scale excavation and construction phase of this transformative infrastructure undertaking.