Aerial photo taken on Dec. 30, 2018 shows the entrance of the Erlang mountain tunnel on the Ya'an-Kangding expressway in southwest China's Sichuan Province. An expressway linking Ya'an and Kangding in southwest China's Sichuan Province went into trial operation Monday morning, marking the total length of expressways in the province at 7,238 km. The construction of the expressway was completed nine months ahead of schedule. It will be the second highway into the Ganzi Tibetan Autonomous Prefecture of Sichuan after the National Highway 318, which leads to Lhasa, capital of Tibet Autonomous Region, said the provincial department of transportation. The newly completed route will enable passengers to travel from Chengdu to Kangding, capital of Ganzi, in only three and a half hours. (Xinhua/Jiang Hongjing)