A Multimodal Traffic Impedance Modeling Framework for a Comprehensive Transportation System

Traffic impedance modeling is fundamental for analyzing the supply–demand characteristics of the comprehensive transportation system (CTS). However, existing studies mainly focus on highway traffic impedance, while the impedance of other transport modes, such as railways, waterways, and airways, has received much less attention. Moreover, most existing models are developed for traffic operation analysis rather than planning, which limits their comparability and practical applicability in CTS analysis. To address this gap, this study develops a unified multimodal traffic impedance modeling framework for CTS and proposes simple and comparable impedance models for highways, railways, waterways, and airways based on their respective travel characteristics. The proposed models are calibrated using real-world field data with R2 values above 0.8. To further verify their effectiveness in large-scale network analysis, the models are applied to the New International Land–Sea Trade Corridor project to evaluate network flow distribution and infrastructure impacts after planned transport projects are introduced. The results show that the proposed models can reproduce network flow trends well and provide quantitative support for evaluating network performance improvement after infrastructure construction. The proposed framework can assist decision-makers in multimodal infrastructure planning and in improving the efficiency and sustainability of CTS.