The construction of the Qinghai-Tibetrailway has proceeded quickly, an expert told Xinhua Friday duringan interview.
"The line is expected to reach the Fenghuoshan observation station, which would extend the now 170-km length of the railway to around 190 kms," said Wang Yinshan, director of the supervision station of the railway project.
"We don't rule out the risk that something unexpected will prevent us from reaching that goal because the construction conditions are so complicated," said Wang.
Workers have to face some tough conditions, such as permanently frozen earth, bitter coldness, lack of oxygen and ecological fragility, he said.
Beginning in 2001, the railway project has so far cost 7.3 billion yuan (884 million US dollars) and is scheduled to be completed by 2007, making it the country's first railway linking Tibet and the rest of China.
With a total length of 1,100 kilometers, the railway will link Golmud, a traffic hub in Qinghai Province, with Lhasa, the regional capital of Tibet, and later will be extended to Shigaze and Linzhi in Tibet, and Yunnan Province in southwest China.