Construction mileage: K255+100～K260+280
Zhaotong ~ Daibu Highway is a section of Chongqing ~ Kunming Expressway (M51), one of the nine longitudinal ways in the planned national “7918” expressway network. With the total construction mileage of 148.809km including the expressway of 38.038km, it is also an important section of the trunk national way (GZ40) Erlianhaote ~ Kunming ~ Hekou Highway in Yunnan Province as well as an important part of the “three-longitudinal, three-transversal and nine-passage” highway network of Yunnan Province. The construction section is located on the north edge of Yunnan-Guizhou Plateau at the boundary of East Yunnan Plateau and West Guizhou Plateau. With relatively large height drop, steep transversal slopes, complicated landform and geological conditions and great difficulties in construction, the project applied controlled blasting technique in stone work excavation. The project was commenced in September 2004, and completed and open to traffic in December 2007.