## 4 Results from the Literature Review
### On-Demand Public Transport
Most research emphasizes the impact of in-vehicle air quality monitoring systems on passenger health, particularly during health crises, such as pandemics [293; 294]. These systems enhance passenger safety by actively monitoring and controlling harmful substances within vehicle cabins. As a result, they help reduce the spread of airborne pathogens, making public transport safer [295; 296]. Contactless Payment Systems  
Contactless payments in public transport allow passengers to pay for rides using a smart card, mobile device, or contactless bank card, eliminating the need for cash or ticket machines. This method leverages near-field communication (NFC) technology, enabling transactions by simply tapping a card or device on a reader. Another option is digital payment through a mobile app, allowing for a seamless, fully digital transaction [297]. Contactless payments provide numerous benefits for both public transport operators and passengers. By removing the need for paper tickets and cash, transport operators reduce costs associated with ticket production, distribution, and storage. Additionally, automating payment processes minimizes the need for ticketing staff, yielding further savings. For passengers, contactless payments offer speed and convenience, shortening wait times at stops, accelerating boarding, and removing the need to carry cash or physical tickets. This convenient system encourages greater public transport use, potentially boosting revenues and decreasing reliance on private vehicles [298; 299]. This shift has a positive impact on urban air quality by reducing greenhouse gas emissions from transport. Research also highlights the role of contactless payments in promoting public health, particularly during epidemics [300]. The COVID-19 pandemic underscored the importance of contactless payments as a crucial element in enhancing sanitary safety for travelers. This solution eliminated the need for contact with staff [301], cash handling, and using ticket machines, thereby reducing the risk of virus transmission [293; 302]. Smart stops and stations are innovative public transport solutions that leverage information and communication technologies (ICTs) to improve travel comfort and safety. Equipped with interactive displays showing schedules, mobile payment options, monitoring systems, and traffic management, these stops provide passengers with better access to information and services, enhancing the quality and safety of public transport [48; 49]. Beyond economic benefits, smart stops and stations are also environmentally friendly. They provide real-time traffic information, boosting transport efficiency and passenger comfort by allowing for better travel planning, with updates on possible schedule disruptions [303]. A key advantage of smart stops and stations is their accessibility, as the infrastructure and informational interfaces can be customized to meet the needs of diverse user groups, including the elderly, disabled individuals, and immigrants. By eliminating barriers, these features can drive higher demand for public transport across all demographics [304]. Research emphasizes the environmental aspect of designing smart stops and stations. Studies advocate for solutions such as smart lighting management and photovoltaic panel installations, with additional support from the public power grid [305]. These innovations, especially when aligned with smart city concepts [49], can significantly reduce energy usage, lower local CO2 emissions, and contribute to better air quality.