Programmable traffic control systems: concepts, architecture, and key technologies

With the rapid development of road traffic infrastructure and vehicle connectivity, the construction of a safe, flexible, and efficient next-generation traffic control system for large-scale road networks has become a critical issue in the industry. To address the challenges of system connectivity, coordination, and scalability in current traffic control systems caused by heterogeneous infrastructure, tight coupling of software and hardware, and a predominantly physical control approach, this paper introduces a software-defined programmable traffic control system based on the concept of parallel transportation with virtual-physical interaction. This system integrated centralized controllers, an application development framework, traffic facility virtualization, and parallel control. These features enable efficient coordination and flexible scheduling of intelligent and connected traffic entities. First, the concept and characteristics of programmable traffic control systems were introduced. Then, the architecture and key technologies were discussed. Furthermore, the system's applications in traffic signal control, priority for emergency vehicles, adaptive traffic sign and marking control, and connected vehicle guidance were discussed. Finally, the development prospects of programmable traffic control systems and related technologies were summarized and prospected. This system can support the next-generation of traffic control systems and provide a foundation for the digital and intelligent transformation of traffic governance.