Abstract for: System Dynamics-DEMATEL Combined Approach to Study the Impact of Integrated Travel Demand Management Policies on Traffic Congestion and Social Equity

Managing road traffic congestion through Travel Demand Management policies can improve traffic performance. However, the impact of traffic congestion management policies on social equity remains contested. An important area that demands further investigation in applying travel demand management policies particularly with push effect is addressing social equity externalities. This study investigates the impact of integrating 3 push-pull Travel Demand Management policies on two seemingly contradicting objectives: reducing traffic congestion and increasing social equity. Qualitative System Dynamics approach is used through Causal Loop Diagrams, combined with Decision Making Trial and Evaluation Laboratory approach. We validate the causal loop diagrams through three-round Delphi approach involving expert participation from six Western European countries. Three policies are modeled, two with push-effect and one with pull-effect, both individually and collectively using causal loop diagrams to examine their dynamics and the effects of policy integration. The results demonstrate that integrating policies with push-effects has strong impact on factors that lead to short and long-term reductions in traffic congestion. In contrast, integrating pull-push policies reduces social externalities on socially disadvantaged population groups. The combined approach proved to be effective in modeling such a complex problem, as it integrates the system dynamics approach with both qualitative and quantitative data collection and validation phases. This integration enables a more comprehensive assessment and validation of the resulting causal loop diagrams (CLDs), ensuring that the identified relationships and feedback structures are supported by both empirical evidence and stakeholder insights. Grammar and sentence structure check