###### Abstract  
Large hospitals in China typically face high-density patient flows, highly concentrated medical service demands, and significant impacts on surrounding transportation systems. To explore this issue in depth, this study selected a sample of 135 hospitals from the Beijing-Tianjin-Hebei region and constructed a structural equation model based on multi-source data to empirically analyze the key factors and mechanisms influencing traffic attraction for different types of hospitals. The findings reveal that medical level is the most critical factor affecting hospital traffic attraction, with significant differences in the factor pathways between general hospitals and specialized hospitals. For general hospitals, hospital size remains an important factor, but the influence of traffic attraction has shifted from traditional static indicators such as construction area and number of beds to more dynamic service diversity indicators, such as the number of medical departments. For specialized hospitals, the second most influential factor is traffic accessibility, particularly the availability of parking spaces, which significantly impacts their traffic attraction, reflecting patients' strong demand for convenient transportation when accessing specialized care. This study highlights the dynamic evolution of traffic attraction factors across different hospital types and provides new insights and theoretical support for optimizing hospital transportation planning and resource allocation. traffic attraction; large hospitals; outpatient volume prediction; structural equation modeling 2020 IEEE/RSJ International Conference on Intelligent Transportation Systems (IEEE), pp. 2284-2290. IEEE. Personal notice on all other things is permitted. Permission from IEEE must be obtained for all other uses, in addition to reprinting, creating new collective works, for example, to reprinting the editors to _Proceedings of the 20 th International Conference on Intelligent Transportation Systems (IEEE), pp. 1-10. IEEE. Personal notice on all other uses is permitted. Permission from IEEE must be obtained for all other uses, in addition to reprinting, creating new collective works, for example, to reprinting the editors to _Proceedings of the 20 th International Conference on Intelligent Transportation Systems (IEEE  
making parking supply a key factor in alleviating peak traffic pressure [3]. Additionally, healthcare visits in China often occur with family members (especially in pediatrics and geriatrics), with an average of two individuals per visit. This group tends to have a higher reliance on private cars for transportation. In China, hospital grade is widely used as a standard to evaluate the quality of medical services. However, research has shown that even hospitals within the same grade can exhibit a three- to five-fold difference in outpatient and inpatient volumes [4]. This finding indicates that relying solely on hospital grade is insufficient to fully explain patients' hospital choices. However, current research lacks a comprehensive analysis of the factors influencing hospital-related traffic flow generation and their underlying mechanisms [5]. Additionally, there are significant differences in the influencing factors across different types of hospitals, further highlighting the need for in-depth research on the interaction mechanisms of these factors. Studying the factors influencing patients' hospital choices is of great significance for hospital planning and optimizing healthcare service systems. Early studies primarily focused on the impact of hospital size on patient attraction, with traditional indicators such as construction area [6] and number of beds [7;8] long regarded as standard metrics for assessing hospital resources. These indicators have been widely applied in national health policies and building regulations.