URUMQI -- Work has started on renovating three key highways in China's Xinjiang Uygur autonomous region as part of the region's efforts to improve transportation infrastructure.

The roads are highways connecting Xiaocaohu, Kuitun, and Dahuangshan in Xinjiang to the regional capital Urumqi, with a total length of 460 kilometers, the regional transportation department said.

The renovation will be finished in three to four years, it said.

Shohrat Zakir, chairman of the Xinjiang regional government, said Xinjiang is scheduled to spend 200 billion yuan (about $29.4 billion) on road construction this year.

The investment is about seven times the figure last year and it exceeds the total amount of money spent on roads during the last five-year period from 2011 to 2015.

"We must step up efforts to improve infrastructure in the region, to better serve the needs of the Belt and Road," said Zakir.

Xinjiang is positioned as a key area of opening up to the west and as a "core area" on the Silk Road Economic Belt, part of the Belt and Road Initiative.