# Intelligent Transportation System Technologies, Challenges and Security
## 1 Introduction  
Intelligent Transportation Systems (ITS) were first conceived as a system in which red and green lights were lit in London in 1868. In this system, red meant \"stop\", green meant \"movement\", and traffic lights were gas powered. It was decided that these systems could be built while the police stood next to them to light the whole day. Traffic increased drastically with the invention of cars, as cities became more crowded with the development of industrialization in the early 1900s. Also, in 1912, [PERSON], an American traffic cop, was the first to develop an electric traffic light [1]. The world's first electric traffic lights entered service on 5 August 1914, and the installed lamp had a height of 5 m. The lights were colored as before, and there was also an audible warning shortly before the lights changed. Electric traffic lights of that time are considered to be the first ITS applications and worldwide projects were developed one after another in the Eastern Inter-Country competitive environment to accelerate the development of ITS: Global Positioning System (GPS)-based route selection, electronic cruise control, in-vehicle systems, as well as traffic lights such as rapid transit systems, dynamic control systems. The accepted form of ITS in international standards also includes road applications. ITS is a system engineering application that uses information and communication technologies to operate and manage the road network's infrastructure and superstructure, which includes intercity and urban roads. To eliminate or reduce the disadvantages that come with the benefits of advanced transportation systems, the concept of ITS has emerged to enable transportation systems to operate more efficiently, environmentally friendly, safely, and economically. ITS has become the focus of various policies and action plans worldwide. When the foundations of ITS studies were examined, Comprehensive Automobile TrafficControl Systems (CACS) in Japan and Electronic Route Guidance Systems (ERGS) appeared in the USA and Germany in the late 1960s. After these years, ITS applications started to become widespread in the mid-1980s. They were first implemented in the 1990s with applications such as electronic toll collection systems, smart intersection control systems, passenger and driver information systems, and traffic control centers. With these practices, cooperation between the public and private sectors has started, and joint projects have been developed. After studies on an international scale began to gain importance, the first ITS congress was held in Paris in 1994 and has continued to take place regularly in a different country every year since then. As a result of these activities and academic studies in ITS, countries have started to establish their own ITS organizations in line with the knowledge gained, emerging technological developments, and needs. In addition to organizations established nationally, regional organizations such as European Road Transport Telematics Implementation Coordination (ERTICO), ITS America, and ITS Asia Pacific [1]. The security of ITS applications is essential in terms of identifying threat factors. Potential security threats include criminal gangs, intelligence from nations, hackers, cyber terrorists, and natural disasters. For example, a nation's ITS infrastructure is in a perilous situation during a war by hostile nations to bring systems down [2]. It is in demand from attackers that ITS applications have a significant impact as a result of attacks. Information can be obtained through physical, wired, or wireless network attacks. When a ransomware attack occurs, the attackers do not give the decryption keys to the other party until the ransom is paid. If a vehicle is accessed after the attack, it cannot function until the ransom is paid. Attacks on these vehicles can generate traffic if a fake vehicle-to-vehicle (V2V) message is transmitted, and this attack can initiate V2V information poisoning.