## 2 Literature Review  
The movement of passengers plays a crucial role in understanding and evaluating the overall service level in public transportation systems. This topic is particularly important for transportation planners, operators, and policymakers, as it directly impacts efficiency, user experience, and overall system effectiveness [9]. Passenger movement refers not only to the physical movement within a transit system but also to how passengers interact with different elements of the transportation network, such as routes, schedules, stations, and the vehicles themselves. Understanding these behaviors can help identify bottlenecks, optimize routes, improve safety, and enhance comfort [10]. Several factors can influence passenger behavior, with fare systems and bus design being two key elements. Fare structures, for example, can directly affect how passengers make decisions about their travel, such as whether they use the service regularly, whether they choose more expensive or less frequent routes, or even how they manage their travel time. A fare system that is complicated, costly, or not well understood may discourage passengers from using public transportation, ultimately leading to reduced system efficiency and increased congestion on certain routes [11]. Similarly, the design of buses or other forms of transportation also plays a vital role in shaping passenger movement [12]. Factors such as seating arrangements, standing space, ease of entry and exit, accessibility for disabled passengers, and the overall comfort of the vehicle can influence how passengers behave. A poorly designed bus can lead to crowding, delays, or uncomfortable conditions, which can deter people from using public transport or reduce the quality of the experience for those who do [13]. In addition to these elements, other factors such as station design [14,15], real-time information systems [16], service frequency and capacity [17], and the level of safety and security [18] can further shape passenger behavior. For instance, well-designed stations with clear signage and easy access can reduce confusion and enhance the flow of passengers, whereas delays in services or inadequate safety measures might prompt passengers to seek alternative travel options, undermining the effectiveness of the public transport system. Understanding the movement of passengers within the context of service-level analysis is essential for improving the quality and efficiency of public transportation. By considering all these influencing factors, cities and transit authorities can create systems that better meet the needs of their passengers, encouraging greater use of public transport, reducing congestion, and contributing to a more sustainable and efficient transportation network. To do so, artificial intelligence (AI) is required [19]. The integration of video surveillance and advanced technologies powered by AI in public transportation systems offers significant opportunities for improving service efficiency, passenger safety, and the overall management of transit networks. By leveraging AI-driven video analysis, transportation authorities can detect and track passengers in real time across various transportation environments, providing valuable insights into how individuals interact with the system [20]. One of the key benefits of using video and AI technologies is the ability to analyze passenger behavior in complex and dynamic situations, such as when passengers are boarding or alighting from an urban bus. These moments are often critical for understanding traffic flow, crowd management, and operational efficiency. For example, AI systems can automatically detect the number of passengers waiting at a bus stop, monitor how they board the vehicle, and track how long it takes for them to enter and exit. These data can then be used to identify patterns in passenger movement, such as peak travel times, delays caused by overcrowding, or inefficiencies in the boarding process [21].