# Urban Traffic State Sensing and Analysis Based on ETC Data: A Survey
## 5 ETC-Based Urban Traffic Management: Applications and Practices
### System Integration and Technology Development Trends  
ETC system technological development is evolving in increasingly intelligent and integrated directions, with edge computing, system security, and multi-technology fusion becoming important driving forces for the deep development of ETC applications. [PERSON] et al. conducted an in-depth exploration of visions and challenges when intelligent transportation system sensing combines with edge computing, noting that the widespread use of mobile devices and sensors has driven the development of data-driven applications that can leverage big data power to benefit many aspects of our daily lives [65]. In system security, [PERSON] and [PERSON] conducted a detailed analysis of intelligent transportation system technologies, challenges, and security issues, noting that protecting ITS infrastructure from cyber attacks has become a matter of national reputation. Providing the necessary technological infrastructure for the integrated operation of the systems used in ITS, particularly geographical location, communication, and mapping, is crucial. The research included the minimum security requirements that might be adopted for ITS applications and infrastructure against these attacks, as well as the most important cyber attacks that might occur in ITS applications [66]. In technology detection and improvement, [PERSON] and [PERSON] developed information-aided intelligent schemes for improving the vehicle flow detection of traffic microwave radar detectors, noting that to achieve satisfactory traffic management in intelligent transportation systems, traffic microwave radar detectors providing real-time traffic information with high precision are crucial [67]. In traffic flow model validation, [PERSON] and [PERSON] compared the traffic flow models with actual traffic data based on a quantitative assessment, proposing universal quantitative methods for evaluating the fundamental relationship models based on real traffic data from Polish highways. The proposed methods aimed to address the problems of finding optimal deterministic models to describe empirical relationships among fundamental traffic flow parameters based on simple transparent criteria [68]. [PERSON] et al. investigated operational and design upgrades for electronic toll collection, examining effective applications of ETC technology in Taiwan highway and expressway planning and design applications, reviewing various design and operational issues, including current AVI/TOLL technology applications, potential operational enhancements, and alternative design upgrades, targeting effective electronic toll collection and electronic toll collection and traffic management [69]. [PERSON] et al. proposed GNSS-based electronic toll collection and road pricing systems, noting that ETC allows charging for road infrastructure use while minimizing traffic interference, achieving better social acceptance, and reducing costs. However, most road pricing strategies today are not based on satellite positioning. The research described the system architecture and operational principles of multi-service ETC systems based on Global Navigation Satellite Systems, the detailed design and functions of three subsystems, and provided a brief analysis of feasibility for GNSS-based road pricing in China [70]. Comprehensively, ETC system technological development has expanded from single toll collection functions to comprehensive traffic management platforms. Edge computing technology applications have made data processing more efficient, system security technology improvements have ensured stable system operation, and the development of multi-source data fusion and intelligent analysis technologies has enhanced system intelligence levels. These technological development trends indicate that ETC systems are becoming important components of urban intelligent transportation systems, providing robust technical support for constructing more intelligent, efficient, and safe urban traffic environments.