# A Multi-Objective Evaluation Method for Smart Highway Operation and Management
## 2 Literature Review
### Current Status of Construction and Development of Smart Highways  
In a broad sense, the concept of smart highways emerged earlier in developed countries, dating back to the 1940s [15], including the United States [16; 17; 18; 19], Japan [20; 21], and the European Union [22; 23]. The policy initiatives and development trends of smart highways in developed countries is summarized in Figure 2.  
Figure 1: Smart highway system facilities and functions.  
Figure 2: Smart highway system facilities and functions.  
The smart highway introduces an innovative approach to highway infrastructure within the contemporary big data era. It signifies an extension and innovation of conventional highway systems, grounded in advanced detection equipment and video monitoring systems [24]. It relies on high-bandwidth network transmission and efficient smart highway information management systems [25]. The primary goal of the smart highway is to offer precise and comprehensive traffic information services for travelers, efficient traffic management services, and decision support for managers. Moreover, it aims to facilitate rapid interconnection among various departments. The smart highway system is focused on management and service, emphasizing data utilization and dissemination, as well as the integration of internal system functions [26].  
The continuous maturation of the internet, big data, artificial intelligence, and other new technologies has driven their deep integration with the development of smart highways. The degree of standardization in smart highway construction is gradually increasing, in addition to the scale of construction. In 2019, the Colorado Department of Transportation (CDOT) in the United States classified roads into six classes, based on their target users and functions, spanning from L1 roads with no installed equipment to L6 roads tailored for advanced autonomous driving requirements [27]. Also, in 2019, the China Highway and Transportation Society classified intelligent transportation infrastructure into levels I0 to I5, where I0 represents no intelligence and I5 represents fully automated driving based on traffic infrastructures [28]. In 2022, the European Road Transport Research Advisory Council (ERTAC) defined the Infrastructure Support Levels for Automated Driving to better support and guide autonomous driving technology. They categorized road infrastructures into five levels, from A (highest, supporting cooperative driving) to E (lowest, no digital information) [29].  
In summary, international attention is focused on the development of smart highways. There are already some available construction standards for smart highways worldwide, and there are also many projects that have been constructed and put into operation. However, the current evaluation standards for facility maintenance and management are generally traditional and do not match the development needs of the facilities. The evaluation standards for smart highways generally remain at the level of overall functional conditions. There has been a lack of quantitative and qualitative analysis and evaluation based on specific road data. Therefore, there is an urgent need for a rational evaluation system for smart highways.