Why are underpasses built for animals on highways?

Kathmandu – Most major road sections in Nepal pass through national parks, national forests, or other types of forest areas. This increases the risk of accidents between wildlife and vehicles.

Among Nepal’s 12 national parks, Chitwan, Parsa, Banke, and Bardiya are connected to the East-West Highway. As a result, animals are often seen on the roads or crossing the highways.

To facilitate the movement of wildlife, the first biological underpasses in Nepal have been constructed at Ramnagar and Aaptari in the Barandabhar forest area of the Narayangadh-Muglin section. These underpasses, designed for animals to pass under the road, need to be tall enough to accommodate large animals as well as small ones, reducing the risk of collisions between animals and vehicles.

Although the underpasses at Ramnagar and Aaptari aren’t fully wildlife-friendly, with local residents and businesses dumping various types of waste there, they were built eight years ago with World Bank financial support. The structures have faced criticism for being only around 12 feet high, making them unsuitable for large animals.

According to the newly established guidelines for wildlife-friendly infrastructure, underpasses should be classified based on their size, with lengths and heights designed to accommodate small, medium, large, and very large wildlife. The underpasses in the Narayangadh-Muglin section are suitable for smaller animals like deer, wild boar, leopards, jungle cats, and monkeys, but not for larger ones like elephants.

The ongoing construction on the Narayangadh-Butwal road section includes 12 wildlife-friendly structures, with some upgraded to allow large animals to pass. Despite the ongoing work disturbing the animals, this section is being improved with consideration for wildlife, influenced by WWF Nepal’s interest in wildlife-friendly infrastructure.

In areas like Parsa National Park, studies for overpasses, overhead bridges, and underpasses have been completed. Bardiya National Park currently lacks such structures, while Banke has a bridge built for testing purposes. In the Narayangadh-Butwal section, gaps are being left in some structures to allow light through, aiding animal crossings.

Constructing such structures at specific intervals on highways connected to national parks and protected areas can help animals reach their destinations safely, supporting wildlife conservation and reducing human-wildlife conflict, says wildlife expert Dr. Roshan Sherchan.