The whole mileage of highway in Chengdu area have been over 1000 miles (1600km), including 4 major trunk lines: Chengdu-Chongqing, Chengdu-Mianyang, Chengdu-Leshan, Chengdu-Ya An. A new highway Chengdu-Nanchong is under construction. To southwest and northwest of China, Chengdu is connected by state freeways including main lines of Chuanzhang (to Tibet), Chuandian (to Kunming), Chuanshan (to Xi'an) and Chuanqing (to Xi'Ning). Inner province freeways also provide convenience to Chengdu to reach every big and small towns within the vicinity of Sichuan province.