The Jingxing Expressway, namely the Jingle Fengrun—Xingxian Heiyukou Expressway, starts in the east at Fengrun Town, Jingle County, Xinzhou City, Shanxi Province, where it connects with the S50 Pinglin Expressway, and ends in the west at Heiyukou, Gaojiacun Town, Xingxian County, Lüliang City, Shanxi Province, where a special Yellow River bridge connects it with the Shenpan Highway in Shaanxi Province. With a total length of 93.86 km, it is the seventh connecting line (Jingle Fengrun–Xingxian Heiyukou) in the Shanxi Province expressway network plan of "three vertical, twelve horizontal, twelve ring and fifteen connecting lines." Its Shanxi expressway number is S48.
The proposed highway starts on the south side of Fengrun Town, Jingle County, Xinzhou City, Shanxi Province, where it connects with the S50 Pinglin Expressway. It crosses the Fen River and runs westward through Sheke Township, Dongcun Town and Shangming Township in Lanxian County, then passes through the extra-long Bailongshan Tunnel to enter Xingxian County. Within Jiaoloushen Township it runs along both banks of the Lanwei River; after crossing the Weifen River, it connects on the north side of Aojiawan Township with the Kelan–Linxian section of the S85 Yourui Expressway (National G59 Hubei Expressway). It fully uses the existing Kelin Expressway section to pass the south side of Xingxian county seat, separates from the Kelin Expressway on the west side of the county seat in Weifen Town, and continues westward through Caijiaya Township and Gaojiacun Town. On the south side of Heiyukou in Gaojiacun Town, Xingxian County, it crosses the Yellow River via a special Yellow River bridge and connects with the Shenpan Highway in Shenmu County, Yulin City, Shaanxi Province.
The route has a total length of 93.86 km (excluding the shared section with the Kelin Expressway), of which 9.5 km is in Jingle County, Xinzhou City; 36.56 km in Lanxian County, Lüliang City; 47.28 km in Xingxian County, Lüliang City; and 0.52 km in Shenmu County, Yulin City. The entire line is built to the standard of a two-way four-lane expressway, with a design speed of 80 km/h and a subgrade width of 25.5 m. The entire line includes 3 extra-large bridges, 78 large and medium bridges, 1 extra-long tunnel, 2 medium tunnels, 4 short tunnels, 6 interchanges, 2 service areas, 1 parking area, 1 mainline toll station, 3 ramp toll stations, 1 monitoring and management sub-center, 2 maintenance work areas and 1 tunnel management station, with a total investment of about 10.6 billion yuan.