# Intelligent Transportation System Technologies, Challenges and Security
## 1 Introduction
Also, security vulnerabilities are possible in ITS to endanger GPS receivers and GPS signal spoofing in vehicles and payment systems [3]. Studies conducted in recent years show that with the increase in awareness about ITS and the tendency of ITS stakeholders to act together, their work has accelerated. For this reason, developing countries need to make ITS planning safe, economical, environmentally friendly, solution oriented, and user-friendly by following ITS stakeholders' views and the relevant ministries' goals. With technology development in ITS, security attacks that pose significant risks have begun to emerge. The fact that there is a danger of death in these areas where security cannot be significantly ensured increases the severity of these attacks [3]. Many research studies have been carried out in this area in the literature. However, in the context of ITS, cyber security and the necessary precautions still need to be adequately addressed. [PERSON] and [PERSON] proposed a new automatic lane change algorithm for designing flexible lane change trajectories in a complex, dynamic environment. This method can design paths during a lane change maneuver with integrated acceleration and turning angle control [4]. [PERSON] et al. studied the current security environment at ITS, and in-depth analysis was conducted to identify missing elements in the design of existing security solutions. In addition, emerging defense mechanisms that provide solutions to the shortcomings of existing countermeasures and new/emerging cyber attacks are introduced [5]. According to [PERSON] et al., Vehicular Ad Hoc Network (VANET) protects privacy and trust management [6]. Potential effects on public safety and system functionality of the critical nature of transport infrastructure and security violations are very important in ITS security. Protecting sensitive data such as traffic flow information, vehicle location data, personal passenger information, access controls, and secure data transmission protocols must maintain data integrity and privacy. It is very important to secure communication networks that connect various components. To prevent unauthorized tampering or manipulation, it is vital to ensure the safety and integrity of the systems. Maintaining physical infrastructure such as traffic signal control cabinets, surveillance cameras, and roadside sensors is essential. Creating resistance and surplus on systems is critical to protect operations in the face of cyber attacks or system failures. To prevent unauthorized access, the identity of users and devices accessing their systems must be verified. To minimize the effect of safety events, it is very important to determine solid event response and recovery procedures. It plays an important role in protecting systems against cyber attacks, such as ISO 27001 [7], NIST Cyber Security Framework [8], and General Data Protection Regulation (GDPR) [9]. This study explains the general definition of ITS and its architecture, applications, and technologies. In particular, ITS applications that can be used in line with the information provided by international standards publishing institutions such as ETSI [10], NEMA [11], and ISO are included. It is emphasized that ITS applications can be used with rapidly developing technology applications such as artificial intelligence, machine learning, the Internet of Things (IoT), blockchain, 5G, 6G, quantum technologies, cloud computing, new generation security algorithms, and big data. Communication technologies used in ITS applications are explained. In addition, security issues and potential cyber attacks against ITS are discussed. Finally, the minimum requirements for security in ITS are discussed.