mobility.

Vehicular Sensor Networks (VSN) provide connected sensor devices to collect data and use it to provide safer and more fluid traffic on the roads [1]. Contemporary vehicles have been fitted with various sensing devices such as actuators, Global Positioning Systems (GPS) [2] devices, and micro-embedded computers [3]. Consequently, many vehicles can collect and process data. Moreover, the vehicles can communicate with other vehicles or with road-side infrastructure using communication protocols such as Hypertext Transfer Protocol (HTTP) [4], Simple Mail Transfer Protocol (SMTP) [5], Wireless Application Protocol (WAP) [6], and Next-Generation Telematics Protocol (NGTP) [7].

The communication paradigm lets vehicles receive and securely send the processed data to other vehicles or infrastructure units. As a result, vehicular technology such as remote engine shutdown and remote vehicle diagnostics, anti-collision systems, and road sign notifications, among others, have been developed. These technologies utilize VSNs to enhance road users' safety, convenience, and comfort. The data collected by sensors used in VSNs is confidential and can be used to harm innocent users. Security in the VSN paradigm is, therefore, critical. Securing VSNs is securing the sensor network against malicious attacks using modern technologies. Advances in the Internet of Things (IoT) have provided opportunities for tremendous technological growth in VSNs. Therefore, to analyze the security aspect of VSNs, we must briefly discuss one of the VSN's main future enablers, IoT, and its security features. Subsequently, providing the reader with a clear understanding of the importance of securing the VSN paradigm.

IoT is a unique system attaining rapid recognition in the world of contemporary wireless telecommunication. IoT will consist of billions of devices, people, objects, and services that seamlessly communicate and exchange information about themselves and their environment. As stated by [8], the next generation of computing will be completely different from the common desktop interactions. The basis of this concept is the rich and ever-growing presence of smart objects and things all around us. Most of these objects will be in the network in one form or another. Such objects include tags, Radio-Frequency Identification (RFID) [9] devices, switches, and so on. With their unique addresses, these "Things" can interact, exchange information, and work together to attain a common goal. For instance, recently, a few cloud-based systems used to provide a plethora of services have been put forward. The cloud-based service connects different devices and provides services to the users [10]. For example, the authors propose Intelligent Transportation Systems (ITS)-cloud [11], a new vehicular cloud-based paradigm used to improve vehicle-to-vehicle communication and security. ITS-cloud provides many services through correspondence, cloud backup, business, and research applications. Security in IoT devices is of utmost importance. Devices should be equipped with built-in security barriers to impediment and isolation, and countermeasures should be recognized, diagnosed, and executed against successful infringements. Currently, VSNs are being employed in a smart city setting.

Smart city implementation can be perceived as mitigating the challenges sparked by the exponential population growth in urban developments. A forecast done by the United Nations Population fund suggests that 60% of the world's population will inhabit urban environments in 10 years. Consequently, 27 megacities with a population of about 10 million are expected to exist in the next 10 years. A vehicular traffic-related problem such as traffic congestion is one of the biggest challenges most significant cities face. Vehicles in the 75 largest urban areas in the US have recently accumulated about 3.6 billion hours of delay. Moreover, this led to 5.7 billion gallons of wasted fuel, translating to $67.5 billion in production loss [12]. As a result, various ways of reducing the cost of transportation are being invented. Utilizing VSNs in the transport sector will save a lot of money by providing a secure data collection and communication system to enable the deployment of services such as efficient traffic routing and accident prevention. Nevertheless, high-security precautions must be employed in VSNs’ paradigms while providing much-needed services.

Fig. 2 illustrates the framework of a smart traffic controlling and monitoring system, highlighting its key components and functionalities. This system integrates various technologies, including IoT sensors, traffic cameras, and communication networks, to gather real-time data on vehicle flow, speed, and congestion levels. The data collected is analyzed using advanced algorithms to optimize traffic signals, enabling adaptive signal control that adjusts timing based on current traffic conditions. This dynamic approach reduces wait times and improves overall traffic efficiency. Additionally, the system incorporates predictive analytics to forecast traffic patterns and potential congestion points, allowing for proactive management strategies. The visual representation emphasizes the interconnected nature of components within the smart traffic system, showcasing how data from multiple sources feeds into a centralized management platform. This holistic view demonstrates the potential for enhanced coordination between vehicles, infrastructure, and traffic management agencies, ultimately contributing to safer and more efficient urban transportation.

A smart city offers a progressive and enhanced lifestyle for the people. A smart city represents a business-oriented and appealing environment. In urban settings, people benefit from different amenities, like PCs, tablets, cell phones, GPS, and sensors.

The estimates for the smart city market are many billion dollars by 2020. This market covers various areas, including smart management, smart movements, smart surveillance, smart transportation [14], smart homes, smart industry, and smart situation handling (Fig. 3).

The IoT would enable clients to oversee and enhance various web devices. A sensor does this procedure to a more prominent degree. They fill in as a connection between the clients and the devices. Sensors gather crude information from ongoing situations and translate it into machine-reasonable organization to effectively exchange it between different "Things." The devices used for deployment of IoT include but are not limited to RFID ,IEEE 802.11, Barcode/QR Code , Zigbee IEEE 802.15.4 and Bluetooth.

Ad Hoc Networks are self-management networks and are divided into various categories. Some categories include (Fig. 5):

I. Mobile Ad Hoc Networks (MANETs) II. Vehicular Ad Hoc Networks (VANETs) III. Wireless Sensor Networks (WSNs) IV. RFID The challenges and issues of different types of ad hoc networks are discussed below. A brief overview of these categories and their connection strategies with IoT is also provided.

The above study reflects the introduction of IoT, ad hoc networks, smart cities, and techniques to interconnect them. The combined work on all these technologies at a time in a traffic congestion scenario is very rarely found.

However, the literature regarding the combination of two or more technologies is presented in this section. This will help the readers to have future directions to work in the area of traffic congestion related to the abovementioned technologies all at a time or a part of them. The work uses GPS and guiding data from the city, which has the correct location of the International Territorial Level (ITLs). This helps the vehicles to find the closest ITL. Every vehicle sends a request message after some interval to get the correct area of each vehicle. This enables us to understand the traffic density. The work depicts a social network of vehicles by clustering the vehicles on a characteristic basis.

This manuscript highlights the different technologies that can help manage traffic in smart cities. The core technologies considered include IoT and ad hoc networks. An overview of these technologies is presented, along with the issues and devices used for communication. It is observed that various devices in IoT and ad hoc work can be used to make a hybrid network for traffic congestion management systems in smart cities. In addition, a brief survey of some intelligent transportation approaches is also presented.

In conclusion, integrating Autonomous Vehicle (AV) networking within smart cities through the IoT represents a significant advancement in urban mobility and infrastructure management. This interconnected ecosystem can enhance traffic efficiency, reduce congestion, and improve safety by enabling real-time communication between vehicles, infrastructure, and various urban services. The potential benefits include reduced emissions, streamlined public transport, and improved emergency response times.

However, realizing this vision is contingent upon addressing key challenges, such as ensuring cybersecurity, protecting user privacy, and developing standardized protocols for interoperability. Effective collaboration among policymakers, technology developers, and urban planners is essential to create a regulatory framework that supports innovation while safeguarding public interests.

As smart cities continue to evolve, leveraging IoT for AV networking offers a pathway to more sustainable, efficient, and resilient urban environments. Future research and development efforts should focus on overcoming existing barriers, exploring advanced technologies, and fostering interdisciplinary partnerships to maximize the societal benefits of this transformative approach to urban mobility.

This research received no external funding.

The data used and analyzed during the current study are available from the corresponding author upon reasonable request.

The author declare no conflicts of interest regarding the publication of this paper.

If necessary, these sections should be tailored to reflect the specific details and contributions.