Using system dynamics to analyze the development of urban freight transportation system based on rail transit: A case study of Beijing

Integrating logistics activities into urban passenger rail transit network (URFT) is regarded as an effective approach to promote urban sustainability and reduce the negative externalities of road-based transportation. This study applied a system dynamics method to simulate URFT system development by focusing on internal operations and external impacts. The characteristics of four major stakeholders (i.e., the government, URFT operator, market, and road freight sector) as well as a series of variables affecting system operations, such as metrics of social and environmental externalities, pricing, investment, and subsidies, were incorporated into two submodels. A case study of Beijing, China was provided to demonstrate the historical validity and rationality of simulation results from 2007 to 2035. Three decision variables (i.e., investment policy, network scale and market competitiveness) were combined into eight distinct scenarios to examine the external benefits, pricing strategies, capital funding structure and business volume of URFT. The findings show that URFT schemes with higher funding and capacity lead to greater reductions in the losses of traffic congestion, air pollution, and accidents. Furthermore, both government support in the early stage and regulation mechanisms among price, supply-demand level, and investment play significant roles in improving the system performance.