Which line is the shortest from Hunan to Tibet?

You'd better take G3 17 in the north of Sichuan-Tibet line and return to Lhasa on Qinghai-Tibet line. Because the Tongmai Bridge is broken, it is difficult to repair it in a short time, so it is not recommended to take the Yunnan-Tibet line or the Sichuan-Tibet line G3 18.

The specific route is as follows: it is easy to get from Hunan to Chengdu, and it is all high-speed. After arriving in Chengdu, take Aba, Luhuo, Ganzi and Dege from G3 17 to Changdu. After arriving in Qamdo, continue westbound along G3 17, pass Wuqi, Dingqing and Baqing to Naqu, and then to Lhasa.

If you come out, you will still follow the Qinghai-Tibet Highway, from Lhasa to Naqu, then cross Tanggula Mountain from Naqu, pass Amdo to Golmud, Qinghai, then go all the way along the Qinghai-Tibet Highway through Qinghai Lake to Xining, and then return to Hunan from Lanzhou and Xi 'an.

Of course, you can also enter from Yunnan and Tibet, but you must bypass the Tongmai Bridge in G3 18, which was broken on August 2. The specific route is as follows: starting from Hunan, passing through Guiyang, Kunming, Dali, Lijiang and Deqin, reaching Mangkang (G2 14) in Tibet, passing through Zuogong, reaching Bangda to the west, and reaching Changdu to the north of Bangda. After that, the route is the same as above, via G3 17 to Naqu, and then to Lhasa.

To go to Tibet now, we must bypass the Tongmai Bridge in G3 18.