A key traffic tunnel group along the State G30 Expressway in Gansu province was officially put into operation on Monday.

Construction on the Wuqianling traffic tunnel group, including five tunnels from Yongdeng county to Gulang county in Gansu province, started in April 2009.

The G30, or Lianyungang-Horgos Expressway from East China's Jiangsu province to the Xinjiang Uygur autonomous region in Northwest China, runs for 4,395 km through six provincial regions. It is the longest expressway linking the eastern coastal area to the northwest border of China.