Framework and operation of digital twin smart freeway

Smart freeway is the newest form of next generation of freeway system which aims to achieve more sustainable objectives utilizing advanced information and communication technologies. Taking the advantages of digital twin on near-real-time interaction between the physical and cyber systems, the framework, operation, and enabled technologies of digital twin smart freeway (DTSF) are developed in this paper. A three-layer conceptual framework is first discussed for understanding the fundamental structure, core components, and operation procedure of a DTSF system in the context of smart transportation. The key technologies of a DTSF system are also investigated, such as simulation modelling, big data analysis, intelligent prediction, and integrated freeway control. Moreover, a well-designed case study based on Simulation of Urban Mobility (SUMO) is provided to verify the efficiency of the proposed freeway control strategy by integrating perimeter control of upstream urban network and traffic regulation of freeway segments. To the best of our knowledge, it is the first time to investigate integrated freeway control under the framework of digital twin.