# Synergies and Potential of Industry 4.0 and Automated Vehicles in Smart City Infrastructure
## 2 Materials and Methods
In the qualitative comparison, the authors focused on the understanding of the individual texts and the observation of the current state of the art in this field, which allowed the authors to qualitatively compare the different elements of smart cities, looking for their synergies. Also, qualitative analysis was used to compare Barcelona and Singapore as leading smart cities. This comparison was also complemented by a quantitative comparison, which is also complemented by specific mathematical figures and data. In fact, all graphs presented in this article contain quantitative data that are compared, for example, year-on-year, but also within specific periods between each other. This combination of quantitative and qualitative comparisons has allowed authors to gain a comprehensive view of the issue and to conduct a broad and clear literature review in this area [10]. The authors examined the historical context and evolution of Industry 4.0 and automated vehicle technologies to understand their emergence, evolution, and current status. This historical perspective provided us with an important framework for understanding current trends and future perspectives. In some parts of our research, the authors used statistical methods to analyze and interpret data collected from different sources. These methods allowed us to quantify and evaluate the importance of different factors influencing the integration of Industry 4.0 and automated vehicles into smart city infrastructure [11]. An extensive literature review was conducted to establish a foundational understanding of existing research on smart cities, Industry 4.0, and AVs. Academic databases such as Google Scholar, Web of Science, and Scopus were searched using a combination of keywords including \"smart city\", \"Industry 4.0\", \"Automated Vehicles\", \"urban mobility\", \"data analytics\", and \"sustainability.\" The inclusion criteria were peer-reviewed articles, conference proceedings, or books published within the past ten years that addressed the aforementioned topics. However, it is always necessary to work critically with relevant data from a variety of sources when analyzing this issue, as not all data from large database sources and large journals may always be relevant [12]. The theoretical basis was obtained from studying a large amount of relevant literature. This theoretical background allowed us to focus on the key elements and the synergistic potential of such integration, while it is important to stress that such a symbiosis can only work thanks to an interconnected infrastructure based on a wide spectrum sharingof data and information. As part of the literature review, the authors also looked at the underlying principles within Industry 4.0, which include and will be described in the next parts of the article, such as automation, data exchange, and the use of intelligent machines within manufacturing and industrial processes. Finally, the literature on AVs was examined, focusing on their potential impact on urban mobility, traffic flow optimization, and safety improvements. By critically reviewing the current literature and current research, the authors have not only provided a starting point for our paper and research but have also identified gaps in this integration and potential places where it could be further improved. The authors have also complemented the theoretical background with a variety of case studies from the field that represent real-world experiences where people can both see and learn from the best. As examples, Barcelona and Singapore are explored below. These cities are directly implementing the above elements in practice, and so, based on their experience, researchers can learn from their mistakes so they are not made again in the future while also revealing weaknesses (such as privacy and data protection) that need to be addressed in the long term so that this integration can work without complications.