Transport authorities in remote China's Tibet Autonomous Region will invest heavily in highway construction for the next five years to provide better access to its rural townships.

Almost 50 billion yuan will be earmarked for highway construction during the 2011-2015 period, a spokesman with the Tibet Autonomous Regional Transport Department said Thursday.

The total length of highways will be extended from the current 58,000 km to 70,000 km by 2015 in the plateau region, the spokesman said.

All rural townships will be connected by highway, he said. Currently, about three quarters of townships have highway links.

In the past five years, China has invested heavily in building transport infrastructure in Tibet, pouring money into construction of highways, railways and airports.

On July 1 this year, Tibet's fourth civil airport opened in its far west Ngari area, shortening a trip to the regional capital Lhasa to one and half hours from three or four days by car.