An expressway linking ancient capital city of Xi'an with Hanzhong City in northwest China's Shaanxi Province, a vital communication line for exploitation of underdeveloped regions in western China, opened to traffic on Sunday.

The expressway, stretching 255 kilometers, runs through three cities and nine counties in southern Shaanxi. It went into construction in 2002 and was regarded as one of China's toughest projects including 540 bridges and 136 tunnels. It costs 13.8 billion yuan to build.

Nearly 70 percent of the expressway meanders amid Qinling Mountains, the habitat of giant panda and other valuable animal and plant species.

To keep away from giant panda habitat and state-listed protected zones for endangered plants and animals, construction experts, after repeated discussions, decided to alter the original route, which extended the road length by 30 kilometers.

The Change of route increased project investment by 1.5 billion yuan (about US$200 million), said Wang Hang, a manager in charge of the project.

"Although it adds difficulties to the construction, it is worthwhile for the protection of rare plants and animals," Wang said.

Apart from giant panda, one rare species is crested ibis, a kind of bird which is believed only to wildly live in China since 1981 when Chinese scientists found seven wild birds in Yangxian County in northwest of the country. To date, the number of crested ibis has surpassed 1,000, including 512 artificially-bred birds.

(Xinhua News Agency October 1, 2007)