A high-speed train runs across a farmland in Binyang County of Nanning City, capital of south China's Guangxi Zhuang Autonomous Region. Picture: Xinhua/Huang Xiaobang

BEIJING China's high-speed railway totaled 19,000 kilometers.

Overall, China plans to invest 3.5 trillion yuan ($504 billion) in railway construction between this year and 2020, 

The plans call for the renovation of expressways and faster construction of railways to serve less-developed regions in central and western China.

Economic growth has steadily slowed over the past six years as communist leaders seek to wean the economy off manufacturing and exports in favor of more self-sustaining growth based on consumer spending.

In the last two years, officials have responded with ramped up spending on construction of highways and other public works.

On Wednesday, China began operating a new high-speed rail line linking the financial hub of Shanghai in the east with Kunming, the capital of southwestern Yunnan province, a poorer region.

The line spans 2,252 kilometers across five provinces, cutting travel time to 11 hours from 35 hours, state media reported.