Against the backdrop of the concurrent advancement of China’s expressway network development and large-scale reconstruction and expansion projects, the reconstruction and expansion of a single road section can trigger a redistribution of the overall traffic flow within the regional road network, with significant characteristics of traffic volume transfer across routes, corridors, and regions. Traditional traffic volume analysis methods, which focus on individual road sections, struggle to meet the practical demands of regional road network linkage, multi-path competition, and dynamic traffic organization. To scientifically grasp the traffic transfer patterns within the road network during reconstruction and expansion and ensure the safety and efficiency of road network operations during construction, this paper adopts a perspective of regional road network linkage to systematically analyze the internal mechanisms and spatiotemporal distribution characteristics of traffic volume transfer during expressway reconstruction and expansion. Furthermore, it proposes a traffic volume transfer forecasting and analysis system suitable for reconstruction and expansion scenarios. Through this analysis, the paper aims to provide theoretical support and practical references for formulating traffic assurance plans for expressway reconstruction and expansion projects, optimizing the allocation of regional road network resources, and preventing and controlling traffic operation risks. This research holds significant importance for enhancing the service level of the road network during expressway reconstruction and expansion.