Most Influential Projects 2021

42 Atal Tunnel

Infrastructure | South Asia

For moving mountains to improve transportation in the Himalayas

Heavy snowfall blankets the main roads to and from India’s Lahaul and Spiti Valley for six months each year, isolating towns and villages from supplies and services, and stifling economic progress. The solution? A 9-kilometer (5.6-mile) highway tunnel through the Rohtang Pass, high in the Himalayan mountains.

Yet the project to build the tunnel proved as treacherous as it was transformative.

Feasibility plans for the Atal Tunnel date back to 1990, but blasting under the mountain didn’t begin until 2010. And then the project was neglected for many years, with only 1.3 kilometers (0.8 miles) completed by 2014. When Prime Minister Narendra Modi took office that same year, he resurrected and fast-tracked the project.

From there, Border Roads Organisation joined forces with contractors Strabag and Afcons to build 1.4 kilometers (0.86 miles) each year. To accelerate progress, the team often tapped innovative techniques, such as sequential excavation, in which workers spray concrete on walls to optimize reinforcements as they dig.

Despite blizzards, mudslides, freezing temperatures and, of course, the pandemic, the horseshoe-shaped double-lane passage opened in October 2020 as the world’s longest high-altitude tunnel.

While the US$438 million project went more than six times over the original budget, there’s expected to be a deep and long-term payoff. For instance, a journey from Manali to Lahaul and Spiti Valley that once required more than four hours now takes just 15 minutes. By slashing travel times, the tunnel serves as a year-round economic artery for the region, allowing the flow of essentials like food and fuel, and giving farmers and horticulturalists easier access to the capital of Delhi and other markets.

And the team incorporated safety features for end users, too: Phones, fire hydrants and air-quality monitors were placed throughout the tunnel, along with emergency exits every 500 meters (1,640 feet) and cameras every 250 meters (820 feet) to monitor for accidents.

"Infrastructure should be developed at a fast pace when the country needs to progress economically and socially," Modi said at the opening ceremony. "Atal Tunnel is going to be a lifeline."