The third and fourth phases of the road network construction BT project in Chengde city are located in Shuangqiao District, Chengde City, Hebei Province. The connecting line from Sidaogou to Nianzigou is 3.16 kilometers long, with a new separated tunnel of 1405 meters in length. The connecting line from Shidongzigou to Nianzigou is 3.09 kilometers long, with a new separated tunnel of 2340 meters in length. The Huancheng West Road (Shuiquangou, Toudaogou) project is 4.7 kilometers long, with a new tunnel of 660 meters.