A kid enjoys the ride on the new high-speed Wuhan-Guangzhou rial line on Saturday.

China will build 42 high-speed passenger rail lines with a total length of 13,000 km in the next three years, covering more than 90 percent of the population.

By 2012, trips from Beijing to most provincial capitals would only take between one and eight hours, said Wang Yongping, the Railway Ministry spokesman.

High-speed rail services from Beijing to Hong Kong are expected to open in three years, cutting the journey from 23 hours to eight. The one-way trip from Shanghai to Hong Kong will be shortened to six hours from the current 18, he said.

High-speed trains not only shorten the distance between cities but also change the speed of China's economic growth, said Wang Xiaoguang, a professor with the Chinese Academy of Governance.

China, a vast country that is often worried about the wide income gap between its highly developed coastal areas and the lagging interior, is looking to the railways to help spread the wealth, he said.

China has adopted a strategy of developing the west and invigorating the central region for about 10 years, thus reducing social and economic imbalances.

But the initiative has been hampered by the slow and expensive transport system, both passenger and cargo. However, "things will change in the future as fast-train lines may help reduce these problems", Wang said.

A high-speed rail line linking Zhengzhou, capital of Henan province and Xi'an, the ancient capital in the northwest Shaanxi province, will be opened soon.

"This will encourage more coastal industries to invest in the northwest where resource and labor costs are lower," Wang said.

Experts also said the upgrade to a high-speed network will allow the old lines to be used for cargo, thus helping inland regions to transport its resources and products efficiently to the eastern ports.

"In the peak traffic season such as Spring Festival ... the railway bureaus have to suspend freight transportation to guarantee smooth passenger flow," Wang said.

"The bottleneck is likely to be eliminated. As high-speed passenger trains ease the pressure on traffic, the railways will focus more on cargo transportation."