Abstract:The reconstruction and expansion of expressways has always been one of the difficulties in highway engineering design, which is not only to make reasonable use of existing facilities and resources as far as possible, but also to meet the demand for traffic growth of reconstruction and expansion, and the reasonable demands of surrounding areas. There is a need to strike a balance between being technically feasible and meeting standards and being economically reasonable and cost-effective. By elaborating the overall design of the G15 Expressway (Jiajin Section) Reconstruction and Expansion Project, the project background, cross-section scale demonstration, engineering scope and plane layout, longitudinal section layout, cross-section layout, overpass and entrance/exit layout, construction traffic organization and other contents are introduced. How to achieve the optimal combination of technology and economy in cross-section scale and layout, and how to reflect the concept of on-demand design in areas with strong demand are discussed in detail, which fully reflect the intensive design concept, and hope to provide some useful references for solving the problems in the reconstruction and expansion of expressways.