LHASA, May 3 (Xinhua) -- More than 83,400 km of roads in southwest China's Tibet Autonomous Region are regularly maintained, up from some 59,700 km five years ago, local authorities said Thursday.

Currently, the maintained roads account for 93 percent of the total length of roads in the region, and 3.75 billion yuan (588 million U.S. dollars) has been spent on maintenance over the past five years, according to the regional highway administration.

Maintenance plays a critical role in ensuring road safety in Tibet, given the geological and climatic environment of the plateau region, said Lu Aiben, head of the administration.

The increasing flow of passengers and goods in recent years has required better maintenance, Lu said.

In addition, the region has renovated or built 219 bridges in the past five years.