India’s Longest Road Tunnels Through Mountain Ranges

India’s road tunnels help people travel safely through mountains. They reduce the need to use passes and roads that stick out in the open.

​Major highway tunnels in India are the Atal Tunnel in Himachal Pradesh, the Chenani–Nashri Tunnel and the Banihal–Qazigund Tunnel in Jammu and Kashmir. These projects make roads easier to use in places hit by snow, landslides and rough ground.

​India is also building the Zoji-la Tunnel. It is a 14.15 km project that will give better road access between Kashmir and Ladakh.

​This guide looks at the operational road tunnels by how long they are. It also tells where they are, how they were built, and why tunnels matter in the region.​

Which Is the Longest Road Tunnel in India?

The Atal Tunnel, which is 9.02 km long, is a little longer than the Chenani–Nashri Tunnel when we look at the tunnel lengths that are usually quoted. Some official Indian sources say that Chenani–Nashri is India’s operational highway tunnel, and they round its length to 9 km. These differences come from variations in the numbers that are published. The Atal Tunnel runs beneath the Rohtang area of the Pir Panjal Range in Himachal Pradesh. The Chenani–Nashri Tunnel lies on National Highway 44 (NH‑44), the road that links Jammu and Srinagar. It is important to tell the difference between tunnels that are already open to traffic and tunnels that are still being built. The Zoji‑la Tunnel has a planned tunnel length of 14.15 km, but it should not be counted among operational road tunnels until it opens.

India’s Longest Road Tunnels Ranked by Length

​The table below shows the operational road tunnels and the main tunnel lengths that are usually quoted. The numbers may differ a little from one source to another, especially when the measurements are rounded.

Note: Sela Tunnel 2 is the main traffic tube of the second Sela tunnel. It is listed here for coverage and not because it is among India’s longest road tunnels. The Sela project also has a 980 m tunnel and the approach roads that go to it. Zoji‑la is not included in this ranking of tunnels because it is still under construction.

Chenani–Nashri Tunnel on the Jammu–Srinagar Highway

Location and Route

​The Chenani–Nashri Tunnel sits on NH‑44 in Jammu and Kashmir between Udhampur and Ramban. It is part of the highway that links Jammu with Srinagar. Before the tunnel opened in 2017, cars had to drive along a mountain stretch of the old road. The tunnel provides a path through the mountains and reduces the need to use open parts of the road that can be hit by bad weather.

Length and Safety Features

​The tunnel is usually said to be 9 km long. It is one tube that carries traffic in both directions and has an escape tunnel for emergencies. The safety systems inside the tunnel are ventilation, cameras, traffic monitors, fire protection and ways to talk to help people. These features keep the tunnel safe. Help manage any incidents that happen inside.

Impact on Travel

​The Chenani–Nashri Tunnel shortens the travel distance along the highway section that it serves and can save up to two hours depending on the journey and road conditions. The Chenani–Nashri Tunnel also reduces the time spent in snow‑affected sections of the route. ​Reliable road access benefits passenger transport, the movement of goods, tourism and local businesses. The Chenani–Nashri Tunnel is therefore important not as an engineering project but also as part of the region’s transport infrastructure. 

Atal Tunnel, Rohtang: Beneath the Pir Panjal Range

​Why Was It Built?

​The Atal Tunnel connects the side of the mountains with the Lahaul Valley in Himachal Pradesh. The Atal Tunnel passes beneath the Rohtang area of the Pir Panjal Range. ​Before the Atal Tunnel was built, heavy snowfall often made Rohtang Pass difficult or impossible to cross during winter. The Atal Tunnel was built to provide reliable access to Lahaul and Spiti without requiring vehicles to cross the exposed pass. The Atal Tunnel was inaugurated in October 2020.​

Length

The Atal Tunnel is 9.02 km long. Lies at an altitude of approximately 3,000 metres above sea level. Construction required engineers to work in freezing temperatures and challenging mountain geology. 

​The Atal Tunnel includes ventilation, lighting, fire‑protection, and monitoring systems. These are essential for maintaining air quality, managing traffic, and responding to emergencies in an enclosed road environment. 

Travel Time Saved on the Manali-Leh Route

The Atal Tunnel reduces the road distance on the route by approximately 46 km and can save around four to five hours according to government information. Actual travel‑time savings depend on the starting point, destination, and road conditions.

By improving access to Lahaul and Spiti, the Atal Tunnel supports tourism, local trade, and the transport of supplies. However, the Atal Tunnel does not guarantee that every road on the Manali–Leh route will remain open in all weather conditions. I believe the Atal Tunnel will bring visitors to Lahaul and Spiti.

Z-Morh Tunnel: Improving Access to Sonamarg

​Location and Purpose

The Z-Morh Tunnel, also known as the Sonamarg Tunnel, is located on NH-1 in Jammu and Kashmir. The Z-Morh Tunnel was inaugurated on January 13, 2025, to improve access between Srinagar and Sonamarg on the route towards Leh. ​

The area experiences snowfall and avalanche risks during winter. By allowing traffic to bypass sections, the Z-Morh Tunnel helps make travel to Sonamarg more reliable. ​

Length and Safety Design 

The main tunnel of the Z-Morh Tunnel is 6.4 km long. It forms part of a larger project that includes an escape tunnel and approach roads. The project is situated at an altitude of 8,650 feet.

​The design of the Z-Morh Tunnel supports movement through the mountain corridor, while the associated infrastructure helps manage emergencies and maintain road connectivity.​

Connection with Zoji-la

The Z-Morh Tunnel and Zoji-la Tunnel are projects along the broader route towards Ladakh. The Z-Morh Tunnel improves access to Sonamarg, while the Zoji-la Tunnel is intended to provide a reliable passage across the higher mountain section between the Kashmir Valley and Ladakh.​

Together, the Z-Morh Tunnel and the Zoji-la Tunnel are expected to reduce the disruption caused by snow and avalanches along this route. ​

Zoji-la Tunnel: The Under-Construction Project

​The Zoji-la Tunnel is an infrastructure project on the Sonamarg–Kargil section of NH-1. The Zoji-la Tunnel’s planned main tunnel is 14.15 km long, making it longer than the operational road tunnels discussed above. A parallel escape tunnel and connecting roads are also part of the project.

​Why it Matters Strategically

The Zoji-la Tunnel is intended to improve all‑weather connectivity between Kashmir and Ladakh. At present, heavy snowfall and avalanches can disrupt travel across the Zoji‑la Pass, affecting the movement of passengers, goods, and essential supplies. ​

The Zoji-la Tunnel is also important because reliable road access is essential in a remote border region. Improved connectivity could support communities, tourism, and the transport of supplies.

Current Status and Planned Length​

According to the National Highways and Infrastructure Development Corporation Limited (NHIDCL), the Zoji-la Tunnel project remains under construction. The published likely completion date is February 28, 2028. This is a projection rather than a guaranteed opening date. ​

Sela Tunnel in the Eastern Himalayas

​Location and Structure

The Sela Tunnel project is located in West Kameng district, Arunachal Pradesh, along the Balipara–Charduar–Tawang road. The Sela Tunnel project comprises two tunnels: a 980 m single‑tube tunnel and a 1,555 m twin‑tube tunnel, which includes a traffic tube and an escape tube.

​The Sela Tunnel project bypasses sections around Sela Pass and improves access to Tawang, where high altitude, snowfall, and harsh weather can affect road travel. ​

Strategic and Regional Importance

​The road toward Tawang is important for residents, tourism, and the movement of supplies. The road also supports defence logistics in a region to the international border with China.

​The Sela project shows how important tunnel infrastructure is beyond Jammu and Kashmir and Himachal Pradesh. In the Himalayas, these projects can improve access to remote settlements and reduce dependence on exposed mountain passes.

Why India Builds Mountain Tunnels​

All-Weather Connectivity

​Mountain roads can be disrupted by snow, avalanches, landslides, and falling rocks. The tunnel allows vehicles to pass through a mountain, crossing an exposed pass. Although tunnels cannot eliminate every weather‑related disruption, tunnels can make important routes more dependable.

Strategic Transport

​Several Himalayan roads serve areas near India’s international borders. Reliable road access supports the movement of personnel, equipment, fuel, food and other essential supplies. The tunnel can reduce journey times. It helps maintain transport links when mountain passes are difficult to use.

Economic and Tourism Benefits

​Improved road connectivity helps businesses transport goods and makes tourist destinations easier to reach. Hotels, restaurants, transport operators and local retailers may benefit from dependable visitor access. The tunnel can also improve residents’ access to education, healthcare and other services. The scale of these benefits depends on road maintenance, environmental management and the needs of communities.

How Mountain Tunnels Are Built​

Excavation Methods

​Mountain tunnels can be built using methods suited to the surrounding rock and ground conditions. The New Austrian Tunnelling Method (NATM) involves excavating in stages, monitoring the rock and installing support as required. Drill‑and‑blast construction uses controlled blasting to remove rock. Engineers select methods according to conditions, tunnel dimensions, safety requirements and project constraints.

Geological Challenges

​Mountain geology can vary considerably along a tunnel alignment. Engineers must account for faults, unstable rock, groundwater, and water seepage. Unexpected conditions can slow excavation. Require additional support or changes to the construction plan. Detailed geological investigations and continuous monitoring help teams respond to these risks.

Ventilation and Emergency Systems

​Road tunnels require ventilation to maintain air quality and remove vehicle exhaust. Lighting helps drivers adjust to changing visibility, while traffic monitoring and communication systems support operation. Fire protection, emergency equipment, and escape routes are also essential. Where a separate escape tunnel is provided, the tunnel offers a route for evacuating people during an emergency.

Conclusion

​India’s major road tunnels improve connectivity through regions where snow, avalanches and difficult terrain can disrupt travel. The Atal Tunnel, Chenani–Nashri Tunnel and Banihal–Qazigund Tunnel are operational links, while the Zoji‑la Tunnel is expected to strengthen connectivity between Kashmir and Ladakh once completed. These projects demonstrate the role of engineering in improving transport reliability and access to areas.

FAQs

1. Which is the longest road tunnel in India?

   ​The Atal Tunnel is 9.02 km long, while the Chenani–Nashri Tunnel is commonly listed at 9 km. Some government sources describe Chenani–Nashri as the operational highway tunnel, so rankings can vary depending on the published measurement. The 14.15 km Zoji‑la Tunnel is still under construction.

2. ​What is the length of the Atal Tunnel?

   ​The Atal Tunnel is 9.02 km long. The tunnel passes beneath the Rohtang area of the Pir Panjal Range in Himachal Pradesh. Connects the Manali side of the mountains with the Lahaul Valley. The tunnel was built to improve access during winter, when Rohtang Pass can be difficult to cross.

3. ​Which is the road tunnel in India?

   The Sela Tunnel is a high‑altitude road tunnel project located at 13,000 feet in Arunachal Pradesh. The tunnel bypasses sections around Sela Pass and improves access to Tawang. Claims about the tunnel can depend on the altitude measured and whether the comparison includes operational or under‑construction projects.

4. ​Which mountain range does the Chenani–Nashri Tunnel pass through?

   ​The Chenani–Nashri Tunnel lies in the region of Jammu and Kashmir along NH‑44 between the Udhampur and Ramban areas. The tunnel provides an alternative to a mountain section of the Jammu–Srinagar highway corridor.

5. ​How much travel time does the Atal Tunnel save?

   ​The Atal Tunnel reduces the road distance on the route by approximately 46 km and can save around four to five hours, according to government information. Actual savings depend on the journey and road conditions.

6. ​Is the Zoji‑la Tunnel open yet?

   ​No. NHIDCL lists the Zoji‑la Tunnel project as ongoing. The main tunnel will be 14.15 km long. The current expected completion date is 28 February 2028. Construction schedules can change. The date should be viewed as a projection, not a guaranteed opening date.

7. ​Are all these tunnels open all year long?

   The tunnels were built to keep roads open when the weather is bad. Year‑round access is not guaranteed in every case. Snow, landslides, maintenance, accidents, or safety bans can affect tunnel use or the roads that lead to them. Travellers should check road alerts before they leave.