On May 15, 2024, the Hankou Tunnel on the Xinjin Expressway, constructed by China Construction Road & Bridge Group Co., Ltd., was certified on site by Guinness World Records as the "World's Longest Highway Spiral Tunnel."

The Xinjin Expressway starts from Kuai Village Camp Village, Dakuai Town, Fengquan District, Xinxiang City, and ends at Yingpan Village, Gujiao Township, Lingchuan County, Shanxi Province, with a total length of 69.75 kilometers. It is an important component of the expressway network plan for northern Henan and a shortcut from northwestern Henan to southeastern Shanxi. The project opened to traffic along its entire line on March 15, 2023; after opening, the travel time from Xinxiang to Jincheng was shortened from more than 3 hours to more than 1 hour.

The Hankou Tunnel is located in the hinterland of the Taihang Mountains in Xinxiang. It is the world's longest small-radius, large-elevation-difference spiral tunnel, 229 meters longer than the previous Guinness World Record holder, the Jinjiazhuang Extra-Long Spiral Tunnel on the Yanchong Expressway.

The spiral tunnel group of the Xinjin Expressway, including tunnels and bridges, has a total length of 28 kilometers, all located in the deep mountainous area of the southern Taihang Mountains at an altitude of 500 to 1,280 meters. There are 9 tunnels in total, with an elevation difference of 780 meters. The entire spiral tunnel group resembles a spiral line, winding and rising two and a half turns inside the "belly" of Jiaoding Mountain in the southern Taihang Mountains.

The reason the Hankou Tunnel is called a spiral tunnel is that a small-radius circular curve was adopted in its design, solving the difficulty of route climbing in mountainous areas by means of spiral line development. The elevation difference between the entrance and exit of the Hankou Tunnel reaches 109 meters—that is, the greatest advantage of the spiral tunnel is that it trades length for height. Although the straight-line distance between the tunnel entrance and exit is only 1.9 kilometers, the actual road winds 4.4 kilometers inside the "belly" of the mountain.

The opening of the Xinjin Expressway connects the Hehui, Yan Taihang, Zhenghui, and Anxin expressways, making it a core hub linking southeastern Shanxi, northern Henan, southern Hebei, and western Shandong.