Kathmandu's Nagdhunga tunnel opens to private cars on a free trial
Cars, jeeps and vans now use Nepal's first modern road tunnel, one-way at first, with hours and vehicle classes to widen after review.
The Nagdhunga-Sisnekhola road tunnel on Kathmandu's western edge opened to private cars, jeeps and vans on 24 August 2026, The Kathmandu Post and OnlineKhabar English reported. The 2.68 km tunnel had carried only emergency vehicles since its inauguration on 27 July. The trial ran one-way, from 9 am to 6 pm, with no toll.
- Rs 29 billionapproximate total cost, according to The Kathmandu Post
- 40 km/hspeed limit inside the tunnel
- Rs 65planned car and van toll for entering Kathmandu
- 42 monthsconstruction time in the original contract; the work took seven years
What happened
For its first month, the tunnel was open only to ambulances, fire engines and other emergency vehicles. From Monday, 24 August 2026, private vehicles with up to nine seats could also use it. The Kathmandu Post called this a trial operation. Kabiraj Shrestha, deputy chief of the tunnel's road safety unit, said the team would study the first week and collect feedback from drivers.
Traffic ran in one direction at first. Department of Roads Director General Bijay Jaisi told OnlineKhabar that two-way traffic could begin within one or two days, depending on how the first operation went. Opening hours would then grow from 9 am to 6 pm, first to 7 am to 8 pm, and later to 6 am to 10 pm. Larger vehicles would be allowed after testing.
The rules are strict. The speed limit is 40 km/h. Headlights must stay on, and stopping and overtaking inside the tunnel are not allowed. Pedestrians, two-wheelers and vehicles carrying flammable goods such as petrol and diesel are banned. CCTV cameras monitor the tube. The trial was free, but tolls are planned for regular operation. Cars and vans will pay Rs 65 entering Kathmandu and Rs 60 leaving.
The project took seven years. Then Prime Minister KP Sharma Oli laid the foundation stone on 21 October 2019. The contract with Japan's Hazama Ando Corporation allowed 42 months, but Covid-19, compensation disputes and other problems caused delays. The escape tunnel broke through in August 2023 and the main tunnel in 2024. The Kathmandu Post puts the total cost at about Rs 29 billion, mostly from Japanese financing.
The engineering behind it
The tunnel has two tubes. The main tube is 2.68 km long and carries two traffic lanes, each 3.5 metres wide, according to Farsight Nepal. A separate emergency tunnel, about 2.5 km long, runs beside it. In general, an escape tunnel gives people a protected path out if there is a fire or crash in the main tube. It also gives rescue teams a safe way in.
A road tunnel needs constant fresh air. Engine exhaust contains carbon monoxide and soot, which build up in a closed space. Farsight Nepal reports that Nagdhunga uses jet fans for ventilation around the clock, along with installed lighting. As general knowledge, jet fans hang from the tunnel roof and push air along the tube. Sensors measure carbon monoxide and visibility, and the control system switches fans on as traffic grows. In a fire, the same fans push smoke in one direction so people can escape the other way.
Most of the safety in a tunnel is electrical and electronic. Lighting must be bright at the entrance, so drivers' eyes can adjust from daylight, and dimmer deeper inside. Cameras, radios, alarms and fire detectors all report to a control room. Farsight Nepal says staff will run the control systems, surveillance cameras, communication equipment and toll systems, and that about 150 staff were to be trained for around two months.
Staged opening is normal engineering practice. Operators first run the systems with no traffic, then with emergency vehicles, then with light cars, and only later with buses and trucks. Each stage tests whether fans, sensors, cameras and staff respond correctly before the load increases. The rules on speed, overtaking and fuel carriers reduce the most serious risk in any road tunnel, which is a fire in heavy traffic.
What it means in Nepal
The Kathmandu Post describes Nagdhunga as Nepal's first modern road tunnel. OnlineKhabar notes that it was built to bypass the busy Nagdhunga road section, where congestion and poor road conditions have long slowed travel between Kathmandu and the western districts. The Balambu flyover, which links the tunnel to the Tribhuvan Highway, opened on the same day.
The tunnel is also a working example that Nepali engineers can study. It shows the full cycle of a tunnel project: geological surveys, excavation, lining, installing electrical and mechanical systems, hiring an operator, and training staff. Farsight Nepal reported in March 2026 that ten companies applied to run the tunnel and that the chosen operator would manage it for five years, 24 hours a day.
The project also shows that finishing construction is not the same as opening. The tunnel was built, then waited for an operator, trained staff and tested systems. Delays on the way came from land compensation and the pandemic as well as from rock and engineering problems. Students who understand the whole chain, from design to operation, can see where a project's real schedule risks lie.
Much of the remaining work in early 2026 was outside the tube. Farsight Nepal listed slope stabilisation near the Sisnekhola portal, safety systems and toll equipment as unfinished in March. It also reported plans for a roadside station called Michi-No-Eki at the west portal, covering 4,650 square metres with parking for at least eight heavy and 25 light vehicles. Portals sit on cut hillsides, so slope protection there is as important as the rock support inside.
What to study if this interests you
In BCE, Engineering Geology II, ENCE 152, in the second semester, covers rock properties and rock mass classification, the basis for choosing tunnel support. Transportation Engineering II, ENCE 353, in the sixth semester, covers traffic studies and traffic control methods, which explain the speed limits, lane rules and staged opening. Engineering Survey II, ENCE 203, in the third semester, includes route surveys, which is how the alignment of a road and its tunnel is first set out on the ground.
In BEI, Instrumentation, ENEX 252, in the fourth semester, covers transducers, interfacing and connectivity in measurement systems. These are the skills behind the carbon monoxide sensors, cameras and alarms that report to a tunnel control room. Students who want to work on tunnel safety systems should also learn how sensors are wired into a control room and how alarms are tested.
Words in this story
- Escape tunnel
- A smaller tunnel beside the main one that gives people a protected way out during a fire or crash.
- Jet fan
- A large fan hung from a tunnel roof that pushes air, and smoke in a fire, along the tunnel.
- Commissioning
- The stage where a finished system is tested step by step before it is handed over for full use.
Where this comes from
- The Kathmandu Post, 24 Aug 2026
- OnlineKhabar English, 24 Aug 2026
- Farsight Nepal, 12 Mar 2026
Written in our own words; no sentence is copied from these reports. Researched with AI assistance on 11 October 2026; no member of faculty has reviewed it yet. If you spot a mistake, call 01-5091616 and we will correct it and say so.
