Nagdhunga-Sisnekhola Tunnel: Nepal’s First Modern Road Tunnel
On July 27, 2026, Nepal inaugurated its first modern road tunnel, the 2.688-kilometre Nagdhunga-Sisnekhola Tunnel, marking a historic milestone in the country’s transport infrastructure. The ceremony, attended by Infrastructure Development Minister Sunil Lamsal, Japanese Ambassador Toru Maeda, and Japan International Cooperation Agency (JICA) President Akihiko Tanaka, highlighted both Nepal’s engineering achievement and the deepening partnership between Nepal and Japan.
The tunnel connects Sisnekhola in Dhunibesi Municipality, Dhading District, with Nagdhunga (Totipakha–Dahachok) in Chandragiri Municipality, Kathmandu. Forming a key link on the Tribhuvan Highway (NH 41), it bypasses the steep, congested, and landslide-prone Nagdhunga–Naubise section, reducing travel time from 30–60 minutes (often longer during peak traffic) to just 5–7 minutes while shortening the route by about 3 kilometres.
Technical Specifications and Safety Systems
The project comprises a 2.688-km, two-lane main tunnel with a 9.5-metre carriageway and an 8.3-metre height, alongside a 2.55-km emergency evacuation tunnel connected to the main tube at intervals of about 375 metres. Built through the geologically challenging Sopyang Formation, the tunnel features Japanese-standard safety systems, including jet-fan ventilation, CCTV surveillance, fire detection and suppression, emergency communication, variable message signs, smart lighting, air-quality sensors, and central control rooms at both portals. A dedicated rescue team will remain on standby around the clock.
The project also includes about 2.6 km of approach roads, bridges, underpasses, an overpass, and the Balambu flyover. Toll plazas use RFID-based N-Tag electronic payment, while pedestrians, motorcycles, three-wheelers, and vehicles carrying flammable or explosive materials are prohibited.
Construction Journey
Construction began after then-Prime Minister K.P. Sharma Oli laid the foundation stone in late 2019. Japan’s Hazama Ando Corporation was the main contractor, while design and supervision were handled by a Japanese-Nepali consultancy team led by Nippon Koei. Originally scheduled for completion in April 2023, the project was delayed by the COVID-19 pandemic, land acquisition issues, difficult geology, and slope failures.
The evacuation tunnel achieved breakthrough in August 2023, followed by the main tunnel in April 2024, with construction completed in May 2026, around 80 months after work began. Japanese engineering expertise played a key role in overcoming the challenging Himalayan terrain through advanced tunnelling and slope stabilization techniques.
Financing and Japanese Cooperation
The project was financed primarily through concessional Japanese Official Development Assistance (ODA) loans via JICA. Japan contributed about 22.3 billion yen (around NPR 21.2–21.5 billion), while the Government of Nepal provided approximately NPR 6 billion, bringing the total project cost to around NPR 29 billion.
Beyond financing, Japan has also supported operational capacity building. During the inauguration, both countries announced a new technical cooperation initiative on tunnel planning, construction, and long-term maintenance, coinciding with the 70th anniversary of Nepal-Japan diplomatic relations.
Commercial and Operational Framework
Operation and maintenance for the first five years have been awarded to the Yusin-ART Joint Venture, a China-Nepal partnership, under a contract worth about NPR 1.1 billion. The operator will manage traffic control, emergency response, inspections, and toll collection, supported initially by Hazama Ando.
Toll rates vary by vehicle type, ranging from NPR 60–65 for cars to NPR 600 for multi-axle trucks. Electronic N-Tag RFID cards facilitate payment, while no tolls will be charged during the initial trial period. The tunnel is expected to eventually handle around 8,000–9,000 vehicles daily, generating annual toll revenue of NPR 300–350 million to support operation and maintenance.
The tunnel has opened in phases, beginning with emergency vehicles for systems testing, before gradually expanding to public transport and private four-wheelers during a trial period of up to three months.
Nepal’s Growing Tunnel Programme
The Nagdhunga-Sisnekhola Tunnel is the first of several major road tunnel projects planned to transform Nepal’s transport network. The 1.126-km Siddhababa Tunnel in Palpa District is around 70 percent complete and is expected to open later this year. Meanwhile, the Kathmandu-Terai/Madhesh Fast Track includes seven tunnels totalling nearly 11 km, including the 3.455-km Mahadevtar Tunnel, which will become Nepal’s longest road tunnel. The government is also studying around two dozen additional tunnel projects across the country.
Impact and Outlook
The tunnel is expected to improve road safety, reduce fuel consumption and vehicle operating costs, lower emissions, and strengthen the movement of people and goods between Kathmandu Valley and western Nepal. Officials believe it could become a model for future tunnel projects across the country.
After more than six years of construction marked by geological, logistical, and pandemic-related challenges, the Nagdhunga-Sisnekhola Tunnel stands as proof that complex mountain infrastructure is achievable in Nepal through international technical cooperation. As full operations begin, it promises not only faster journeys into the capital but also a more resilient and modern national road network.
