Because of the harsh natural reality, the Tibetan area’s traffic is uniquely not as convenient as most other places throughout history. Currently however, more and more transporting options are becoming available to reach Tibet, as the Lhasa Gonggar Airport are opening more lines and the Qinghai–Tibet Railway line was connected to the Chinese railway net at 2006. Traveling by cars is also an option, as the conditions of the Sichuan-Tibet line and the Yunnan-Tibet line improve.
On road, there are so far three directions to enter Tibet, from China, there are four lines connected to Lhasa from Sichuan, Yunnan, Xinjiang and Qinghai, and from Nepal, Kathmandu is also connected to Lhasa by road. The Kathmandu to Lhasa route, however, is frequently influenced by weather, as the south side of the Himalayas can be very dangerous for cars in monsoon seasons, and the road condition is rather poor. in terms of China, the Xinjinag-Tibet route can get harsh as well as the trip needs to across numerous grand deserts. The Qinghai route has a thorough highway and the best road condition and yet there is not that much to see during the trip. The Yunnan route, is probably the most beautiful one and has the lowest average altitude, as it crosses forests and grasslands throughout Yunnan and southern Tibet. Finally the Sichuan route, has the most cultural landscape, and yet road jumps rapidly between different terrains and landslides are very usual.
Meanwhile, a train trip is maybe the most popular option, as the steady and safe cabins take you through astonishing landscapes, and yet the tickets can be hard to get in certain seasons, as the Q-T trains strictly controls overloading, since the train’s oxygen supply can run short if too many people are on board.
Flying to Tibet is the fastest and safest way, as you can fly from China or Kathmandu, Nepal, but the trade off is all the beauties on the road, on which I strongly recommend against skipping.