# Urban Traffic State Sensing and Analysis Based on ETC Data: A Survey
## 2 ETC Systems: Historical Development and Current Applications
### Global ETC Development History Overview  
The development of ETC technology worldwide exhibits distinct gradual characteristics, experiencing an extended development cycle from technical validation to large-scale application while accumulating rich experiences and mature technical solutions [6; 7; 8]. As a pioneer in ETC technology, the United States' development experience offers significant reference value. American highways are generally toll-free, with toll roads accounting for less than one-tenth of the total mileage. However, ETC technology has been fully applied and validated on the limited toll segments. A key characteristic of the American ETC system is regional development, with states initially building their own systems and later achieving regional integration through negotiations. E-ZPass became the unified brand for 16 northeastern states, while Sun-Pass covers three southern states: Florida, Georgia, and South Carolina. The success of American ETC development lies in its flexible business models and user-friendly design concepts. [PERSON] and [PERSON] found in their research that appropriate ETC lane configuration and reasonable fee discounts are key factors in improving overall system efficiency [9]. American experience demonstrates that ETC system success depends not only on technology itself but more importantly on establishing reasonable business models and incentive mechanisms. Japan's ETC development trajectory demonstrates a complete path from technology introduction to comprehensive adoption, providing valuable insights for understanding ETC technology promotion patterns. In 1997, Japan's ETC toll collection system conducted its first trial operation on the Odawara-Atsugi Road. Through long-term technical accumulation and market cultivation, it eventually achieved large-scale adoption. Research by [PERSON] et al. indicates that mixed lane configurations and dynamic lane switching strategies can maximize ETC system benefits [10]. The distinctive features of Japan's ETC development include continuous technological upgrades and systematic policy support. The national promotion of the ETC toll collection system began in late November 2000, but the initial adoption was relatively slow due to complex credit card application procedures and high OBU equipment prices. By implementing equipment subsidies, fee discounts,convenient services, and other measures, Japan upgraded to ETC2.0 in 2015, achieving more intelligent management through big data and internet technologies. By 2017, the number of vehicles equipped with ETC exceeded 70 million, with ETC usage rates surpassing 90%. Singapore's Electronic Road Pricing (ERP) system represents an innovative application of ETC technology in urban traffic management. Officially implemented in September 1998, this system employs dynamic pricing strategies, establishing different toll standards based on road traffic speeds and regulating traffic demand through economic leverage. Singapore has successfully applied ETC technology to urban intelligent transportation systems, with ETC parking and ETC payments becoming routine aspects of Singapore travel. The success of this model validates the enormous potential of ETC technology in urban traffic demand management. China's ETC development exhibits distinct policy-driven characteristics, demonstrating the advantages of centralized coordination and extraordinary development capabilities. Unlike the gradual development abroad, China's ETC construction has followed a leapfrog development path. China's ETC development can be divided into three phases: the pilot exploration period (1998-2010), the steady development period (2010-2019), and the rapid adoption period (2019-present). In 1998, the ETC toll collection system began its trial implementation in Guangdong Province. After more than 20 years of development, it gradually expanded from regional pilots to nationwide networking. This development process reflects the gradual and systematic characteristics of China's new technology promotion and application.