## 2 Literature Review
### Regulations and Privacy Concerns about FRT  
Although advanced technologies could improve traffic safety, there are drawbacks at the same time. The main problem is the risk of privacy invasion since these technologies can collect, store, and share personal information [39]. For example, privacy and safety are the main concerns expressed concerning traffic enforcement drones, and the citizens once opposed this technology in Los Angeles. They felt the department would use drones to track and observe them [40]. Privacy concerns are also reflected in in-vehicle data recorders. This concern tends to hinder the acceptance of innovations [41]. There are limited studies on the application feedback of FRT in recognition of red-light running behavior. However, numerous studies have conducted public surveys about FRT application, indicating their concerns about privacy invasion. In many cases, their facial information is collected involuntarily [42], which may lead to undesirable results of intrusions of privacy [43]. The privacy concerns are affected by privacy control, which means giving users the autonomy to control their private information [44]. The legitimacy of FRT contributes to allay, deaden, or possibly circumvent privacy concerns. In other words, FRT with less legitimacy could heighten people's concerns about privacy [45]. FRT also raises concerns about control over personal information, where it is used, and the potential for misrecognition [46]. These concerns about privacy invasion that FRT may cause have attracted worldwide attention. The application of FRT for legal regulation has become the focus of legislative protection in various countries. Many states in the US have issued several bills about FRT. Government agencies in the US are cautious about using FRT and focus on prohibitive regulations. For example, the Body Camera Accountability Act states that the operation of FRT with a camera is an invasion of personal privacy [47]. Non-governmental organizations in the US are more open to using FRT, and they allow the restricted use of FRT to a certain extent. For example, Illinois proposed the Biometric Information Privacy Act (BIPA) to regulate the collection, storage, use, retention, and destruction of biometric information, including facial feature information, through individual empowerment and enhanced obligations [48]. The EU also restricts the application of FRT strictly. The General Data Protection Regulation (GDPR) incorporates different types and properties of personal information and protects personal information through civil, administrative, and criminal measures. In exceptional circumstances, the processing must meet the requirements of legal, legitimate, consent, and voluntary [49]. In China, the protection of facial features about FRT is distributed in laws and regulations. The Civil Code became effective on 1 January 2021, stipulating a natural person's personal information is protected, and the personal information mainly includes a name, birthday, and ID number. However, the Civil Code does not stipulate the contents and methods of protection expressly. China has announced more detailed regulations on the facial feature information involved in applying FRT in administrative regulations, rules, and other normative documents. Information Security Technology-Personal Information Security Specification revised in March 2020 explicitly regulates that personal biometric information is sensitive personal information. Sensitive personal information needs special protection. For example, before collecting personal biometric information, the subject should be informed of the purpose, method, and scope of personal information, storage time, and other rules, and the subject's consent should be obtained. Personal biometric information should be stored separately from personally identifiable information. In principle, original personal biometric information should not be stored. However, these regulations are only recommended and not mandatory [50].