China has completed building a highway including a 2km mountain tunnel in a remote part of southeastern Tibet Autonomous Region (TAR), which ends near the border with Arunachal Pradesh, posing a security challenge to India.
The highway cuts through the world’s deepest canyon, the Yarlung Zangbo Grand Canyon, and its likely terminus is Baibung county (known as Drepung in Tibetan), close to the Indian border village of Bishing in the Upper Siang district of Arunachal Pradesh.
The village of Bishing is located in Arunachal’s Gelling circle, which touches the McMahon Line, the de-facto Sino-India border in the region.
The highway is part of China’s ambitious plans to build roads and tunnels along the length of the Line of Actual Control (LAC) with India, connecting far-flung areas to inland cities and airports.
The new highway has cut down the travelling time between the Chinese border county and the nearest city area of Nyingchi prefecture by eight hours.
The highway is also expected to play a key role in the surveying of and planning for the mega Yarlung Zangbo hydro-power project China is planning to build at the canyon in the same Medog county, triggering unease among downstream countries like India.
Rising in TAR, the Yarlung Zangbo flows into Arunachal Pradesh as Siang, and then as Brahmaputra in Assam before flowing into Bangladesh.
The construction of the highway passing through the world’s deepest canyon with a maximum depth of 6,009 metres was completed on May 16, Chinese state media reported.
It was completed after the Laohuzui 2,114-metre tunnel was built on the 67.22km road connecting Pad township in the city of Nyingchi and Medog county near the India border.
The project, which was executed by China’s Huaneng Group, started in 2014, and cost 2 billion yuan ($310 million).
The highway was completed 228 days ahead of its scheduled opening. “It is the second significant passageway to Medog, following the first one connecting the county and Zhamog township in Bomi county. After the new highway opens to traffic, the road length connecting the city of Nyingchi and Medog county will be shortened to 180km from 346km, cutting travel time by eight hours,” Xinhua reported.
The highway was built on the “…former hiking route between Nyingchi’s Pad township and Baibung township, Medog county, with an altitude difference of up to 2,892 metres between the highest and lowest spots of the road”.
All the places named in the state media report are located near the border with India.
“This road has obviously an important strategic significance, first due to the proximity of the border/LAC and also due to the fact that all infrastructure development in the TAR is dual use, military and civilian. It also means more tourists at the border,” India-based Tibet specialist Claude Arpi said. “The new route will probably facilitate the survey for the mega hydro power project announced as part of the 14th Five-year plan.”
Interestingly, in December, in a report on the highway, the official Tibet news website had said that the constructing the highway had proven difficult and the project was affected by geological disasters such as heavy rain during the flood season, ice and snow in winter, landslides, mudslides and avalanches.
In 2018, a landslide caused by a melting glacier blocked the Yarlung Zangbo at the Sedongpu Basin in Milin county, close to the proposed site of the dam, forming an unstable lake of around 600 cubic metres of water, the Hong Kong-based South China Morning Post (SCMP) reported in April.
Across the border, India is also building a 150-km-long Yingkiong-Bishing national highway in the Upper Siang district.
Arunachal Pradesh health and family welfare minister Alo Libang said in November that the satellite survey for construction of the highway had been completed.

