Atal Tunnel, Rohtang
A single-tube, two-lane road tunnel at about 3,000 m altitude that keeps Manali connected to the Lahaul-Spiti valley all year.
Project at a glance
| Location | Under the Rohtang Pass, Pir Panjal range, Himachal Pradesh |
|---|---|
| Owner / agency | Border Roads Organisation (Ministry of Defence) |
| Completed / opened | 2020 |
| Sector | Tunnels |
| Length | 9.02 km |
| Shape | Horseshoe, single tube, two lanes, two-way traffic |
| Roadway | 8 m carriageway |
| Overhead clearance | 5.525 m |
| Portal altitudes | South 3,060 m; North 3,071 m above mean sea level |
| Design traffic | 3,000 cars and 1,500 trucks a day, up to 80 km/h |
Construction technology used
- A fire-proof emergency egress tunnel of 3.6 m × 2.25 m is built into the main tunnel itself.
- Semi-transverse ventilation, with SCADA-controlled firefighting, lighting and monitoring.
- Safety systems at close spacing along the tube: fire hydrants about every 60 m, emergency phones about every 150 m, incident-detection CCTV about every 250 m and air-quality monitoring every kilometre.
Design and construction challenges
- Freezing temperatures and very difficult mountain terrain.
- The 587 m Seri Nala fault zone was the hardest stretch to tunnel through.
- Breakthrough from both ends was achieved on 15 October 2017.
Key facts
- Cuts the Manali–Leh road distance by about 46 km and travel time by about 4 to 5 hours.
- Before the tunnel, the valley was cut off for about six months a year by snow.
Learn the engineering behind it
- NATM · Tunnel Engineering
- Ventilation and fire safety · Tunnel Engineering
- Tunnel support design · Rock Mechanics
- Geology for dams and tunnels · Engineering Geology
Watch on YouTube
Sources
Facts on this page are taken only from official or authoritative sources (owner agencies, government releases, designers and contractors) and written in our own words. A figure is shown only when we could confirm it from at least two of the sources below; anything we could not confirm is left out. Spotted an error? Tell us.
Author: Indiacon. Last reviewed 24 Oct 2026. Educational summary; not an official project document.