In the modern era, transportation systems play a prominent role in almost all aspects of life. Intelligent Transportation Systems (ITS) are transportation technologies capable of improving the performance of roadway systems via advanced wireless communication technologies. They can dramatically change everything related to mobility, from driving behavior to vehicle manufacturing methods (Gupta et al., 2020). ITS is an innovative solution for modern transportation issues. It can enhance safety, mobility, and efficiency through sensing, analysis, control, and communication technologies, as well as management strategies for ground transportation. There is a wide range of technologies involved in the development of ITS. These technologies can be classified into several groups including (European Commission, 2012):
Communication: Intelligent Transportation Systems (ITS) is comprised of two main communication methods, wired communication (e.g., Fiber optic and twisted pair wires) and wireless communication (e.g., UHF, VHF, WiMAX, GSM, Infrared, microwave, radio, and cellular technology).
Sensing technology: Different kinds of sensors have progressed thus far. For example, weather sensors like rain gauges in particular have been heavily employed in transportation networks.
Data acquisition: Cameras and RFID scanners collect data from the transportation networks. Traffic can be checked through inductive loop detectors and traffic sensors, like radar and video image detectors (VIDs).
Data processing: Computers, satellites, sensors, GPS, and the internet are playing a prominent role in transportation systems because they govern data processing, and providing the data to policymakers.
ITS mainly consists of the following components (Qureshi and Abdullah, 2013):
active traffic management (ATM)
traffic cameras (CCTV)
highway advisory radios (HAR)
road/weather information systems (RWIS)
traffic management systems (TMS)
traveler information systems (TIS)
global positioning system (GPS)
Some of these technologies are already employed globally (Gupta et al., 2020; Qureshi and Abdullah, 2013):
Electronic toll collection (ETC): This can recognize registered vehicles. ETC automatically takes money out of the accounts of registered drivers and informs law enforcers in case of infringements. This process can maximize efficiency, mobility, and lead to faster toll collection.
Ramp metering (RM): This technology is employed in freeway ramps in order to control traffic flow and increase roadway capacity.
Red light camera (RLC): This system is utilized in traffic management, and controlling traffic violations at intersections.
Transit signal priority (TSP): TSP prolongs the green time duration for public vehicles when necessary.
Many countries are currently developing exhaustive national techniques to make use of ITS in upgrading their transport systems. Nations can take advantage of ITS in several ways (Gupta et al., 2020).
First, ITS increases the capacity of the transportation infrastructure; so, the need to build extra roadways decreases. Government administrators support this technology due to its commitment to considerably improve the performance of available transportation systems.
Second, safety is one of the main stimuli for the execution of ITS applications. The ITS programs assist drivers in facing today’s traffic challenges, including unauthorized speeds, vehicle crashes, inclement weather conditions, and traffic congestion. ITS improves safety, diminishes road risks, enhances mobility, maximizes traffic efficiency, optimizes sustainability, and reduces traffic problems in several conditions.
Third, ITS can lead to a reduction in infrastructure damage. Indeed, overload vehicles can put remarkable pressure on the roadway and harm it; so, weigh-in-motion systems can assess the weight of moving vehicles and recognize overloaded vehicles.
Forth, ITS makes traffic signals actuated, in which traffic signals can act based on the varying situations automatically, rather than on a fixed program. This can prioritize different movements and can create smoother traffic.
Fifth, ITS provides a smart parking control system that can inspect prohibited parking and overstaying drivers.
Six, with the rising communications among vehicles, infrastructure, people, and other entities, noticeable amounts of data are being produced. Government and policymakers can make use of the saved data via ITS.
Finally, ITS plays a pivotal role in minimizing the adverse environmental effects of transportation and accomplishing sustainable development requirements.
To look at the history of ITS applications in different communities, we term first to the US. The US Department of Transportation (USDOT) launched the introduction and development of the US national ITS technology in 1993, and this plan needs to be applied to all new ITS projects in order to receive federal funding (FHWA, 2016). One of the most prominent indications of recent ITS achievements in the US, is that more than 1800 research studies have been accomplished at the smart road test site in Virginia to analyze autonomous vehicles, network technology, and smart transportation systems. The most important feature of this site is the deployment of a road system with the ability to simulate weather conditions (Xu et al., 2019).
Other developed areas have recently exerted similar efforts to introduce a national ITS framework, and promote the communication facilities of some test roads in order to pave the way for completing fully automated driving (Xu et al., 2019). For example, Japan introduced an Automated Driving System Research (ADSR) plan in 2014. The main goal of this program was to improve and verify the automated driving system (ADS) for safer operations on public roadways (Yamamoto, 2015). Moreover, In Europe, the proposed “Horizon 2020” plan incorporates the structure for safe automated road transportation. Indeed, many European nations such as the United Kingdom, Germany, and France, are already involved in autonomous vehicle systems research within their authorities (ERTRAC, 2015). Also, other developed nations including South Korea, Canada, Australia, and Singapore are carrying out some research projects on autonomous vehicles (Khan et al., 2017).
Despite all the benefits of ITS, many countries cannot invest much in this technology. This is partly because of the ITS deployment issues that consist of the following (Gupta et al., 2020)
Privacy: It is believed that the use of ITS may threaten the users' security and privacy, which is the main concern during tracking people and vehicles. Data privacy and security can be susceptible in a wireless communications environment since law enforcement agencies are typically interested in private information like locations traveled and driving behavior (Lederman et al., 2016). Network hackers can aim at ITS, and cause traffic disruption and accidents; hence, the data may be refined for privacy or protection.
Standardization: The development of ITS applications has generated compatibility and interoperability challenges at national and international levels. Therefore, developing new ITS programs within and across nations is crucial (Smith and Venkatanarayana, 2005).
Interoperability: This is related to how to efficaciously the system can make a connection with other network components, regardless of their location. As our environments become more connected, this issue should be considered more than ever before (Gikas et al., 2019).
Awareness: Governments and ITS experts should be capable of persuasive debates with the people so that the shift from ITS adoption to large-scale implementation can be facilitated, and the investments in this field can be justified (Laña et al., 2021).
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