Qixingping Tunnel, a key project on the Xi'an-Chongqing High-Speed Railway, achieved a major breakthrough on Tuesday. The 13.7-km tunnel in Dazhou City, southwest China's Sichuan Province, is the second longest on the Ankang-Chongqing section and the only one with a bifurcated "swallow-tailed" structure. Designed for speeds of 350 km/h, the Xi'an-Chongqing High-Speed Railway is expected to cut travel time between the two cities from five hours to about two when completed in 2028.