## 2 Theoretical Background of Bike-Sharing Systems
### Bike-Sharing System in the Light of Scientific Research
Numerous studies have demonstrated their capacity to reduce greenhouse gas emissions, improve air quality, and alleviate traffic congestion by encouraging a modal shift from private motor vehicles to bicycles. This transition supports broader urban sustainability goals and contributes to the development of cleaner, more liveable cities. [PERSON] et al. conducted an in-depth study of bike-sharing systems in Chinese cities, quantifying their effects on CO\({}_{2}\) emission reduction. Their research revealed that bike-sharing not only replaced short car trips but also reduced dependence on motorised transport for last-mile connectivity, substantially contributing to urban air pollution mitigation [52]. Likewise, [PERSON] et al. examined the impact of bike-sharing on modal shift in various global cities, highlighting that a considerable share of bike-sharing trips substituted car travel [53]. This shift was especially pronounced in areas where bike-sharing systems were effectively integrated with public transportation, offering users a seamless and environmentally friendly multimodal travel option. In addition to replacing car journeys, bike-sharing has been shown to reduce urban traffic congestion. [PERSON] et al. found that these systems provide a low-impact alternative to private vehicle use, particularly during peak hours [54]. This reduction in congestion yields further environmental benefits, including lower emissions from idling vehicles and improved fuel efficiency for other road users. The social dimensions of bike-sharing initiatives have been extensively studied, with particular emphasis on issues of equity, accessibility, and inclusiveness. These systems presents unique opportunities to address mobility challenges for underrepresented populations by providing affordable transportation options in areas where public transit may be limited or unreliable. However, despite their potential social benefits, significant barriers to equitable access still exist, raising critical questions about how bike-sharing programmes can be designed and implemented to maximise their social impact. A notable advantage of bike-sharing initiatives is their potential to enhance transportation access for low-income and marginalised communities. [PERSON] and [PERSON] examined equity-focused policies in bike-sharing programmes across the United States, finding that subsidies and targeted outreach efforts can significantly increase participation among low-income and minority groups [55]. In addition to improving mobility, bike-sharing programmes can foster community engagement and social cohesion. Research conducted by [PERSON] et al. found that bike-sharing enhances the liveliness of urban communities by promoting interaction among residents and diminishing social isolation [56]. Moreover, encouraging active living through cycling has been recognised as an important social advantage, with studies showing that frequent use of bike-sharing can improve both physical and mental health. These advantages are particularly important in urban environments, where sedentary lifestyles and long-term health conditions are increasingly prevalent. Technological and operational innovations have played a pivotal role in transforming bike-sharing systems from basic community services into sophisticated urban mobility solutions. The integration of digital tools and innovative operational models has significantly enhanced user experience, increased operational efficiency, and enabled scalability, while also facilitating integration into broader urban transportation ecosystems. A key technological advancement in the evolution of bike-sharing systems has been the adoption of information and communication technologies (ICT). These include GPS tracking, mobile applications, and digital payment systems, all of which have reshaped how users interact with bike-sharing services. ICT innovations support real-time bicycle availability tracking, seamless payment processing, and route optimisation [57; 58].