Bengaluru-based writer and educationist Chandrika R. Krishnan has made five visits to the mountains in North India in the last decade. And each time, her road journeys have gotten delayed because of landslides.

“I remember waiting it out in Kashmir, Ladakh and Uttarakhand because rainfall-triggered landslides had temporarily blocked the road,” Krishnan told ISignal.

Some of these visits were outside the monsoon window. Krishnan visited Leh and Ladakh in August 2019, Char Dham (the four sacred Hindu Himalayan shrines) in May 2022, Amarnath and Kashmir in May 2024, Adi Kailash in June 2025, and Vaishno Devi in October 2025.

While hilly roads are known to be prone to landslides, studies show that road construction—which the Himalayan region (and India as a whole) has seen a lot of in the last decade—can contribute to both their frequency and magnitude.

In March 2025, researchers published a landslide susceptibility map for an 80-km stretch from Karnaprayag to Joshimath in Uttarakhand along National Highway 7, a mountainous corridor connecting Punjab, Haryana, Himachal Pradesh and Uttarakhand. The study demarcated areas into five categories of susceptibility: very low, low, moderate, high, and very high. Both the high and very high zones majorly lay alongside the road, a sign that “road widening, construction works, etc. are significantly causing the slopes to be more prone to landslides”, they concluded.

In the Himalayan region, road construction frequently involves cutting into steep slopes with complex geological and hydrological conditions, explained Satish Pandey, scientist F & head, Flexible Pavement Division, CSIR-Central Road Research Institute, under the Ministry of Science and Technology.

Geological surveys, drainage characteristics, groundwater conditions and landslide susceptibility must be considered at the planning stage, Pandey said. If not, road construction can increase slope instability. Without adequate stabilisation and drainage, and given the concentration of surface runoff, it can further increase the risk of landslides, erosion and road damage during intense rainfall, he explained.

“Even in flood-prone areas that aren’t hilly, roads and bridges can become vulnerable when the design does not adequately account for catchment hydrology, changing runoff conditions, floodplain behaviour and river morphology,” added Pandey, who is also a professor at the Academy of Scientific & Innovative Research.

For example, inadequate assessment of the highest potential overflows, or inadequate provision for those overflows to drain, or insufficient consideration of the washing away of the riverbed material around the base of structures can increase the likelihood of damage or structural distress to embankments during major flood events.

New lessons, even as old ones are ignored

With climate change, particularly heavy rainfall, increasing the hazards facing infrastructure and habitations, experts said road design needs to be revisited.

“Climate change is necessitating the analysis of multiple variables to design infrastructure that can withstand potential disasters,” said Dikshu Kukreja, Principal Architect, CP Kukreja Architects.

For instance, during the February 2021 Rishiganga valley disaster, a road bridge constructed by the Border Roads Organisation near Raini village in Uttarakhand’s Chamoli was destroyed, along with other bridges and sections of road infrastructure. The National Disaster Management Authority’s detailed assessment of the disaster found that the exceptionally complex combination of rock-fall, ice break-off, debris flow and extreme sediment transport was of a scale that exceeded previously observed flood conditions and caused enormous sediment deposition and changes to the river channel.

Essentially, bridge and road planning in vulnerable valleys cannot look only at conventional data impacting road longevity such as river discharge data. “It has to account for cascading hazards, including debris flows, sudden channel blockage and avulsion [switch of a river course], and changes in the river’s morphology,” said Kukreja, who is also co-author of The Future of the Himalayas, a whitepaper on rethinking development and resilience in that region. “Different datasets must be brought together at the point where an infrastructure decision is made.”

While India has considerable technical expertise and a growing body of information on rainfall, floods, geology, terrain, landslides and climate variability, Pandey said, the extent to which these datasets are integrated into project planning, design, construction and maintenance can vary considerably across projects and agencies.

Manmohan Singh Deol, technical director, Rodic Consultants, said that hazard findings mapped by studies sit largely in academic literature and internal project reports. He suggested that they should feed into a live, updated risk register, and that project........

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