Urban public transport system accessibility for different groups of residents: Case of Bratislava city

The main goal of the article is to characterize the functioning of the Urban Public Transport System (UPTS) in the capital city of the Slovak Republic (Bratislava) during different time periods (morning rush, evening, night, average working day, and weekend - Sunday) and express its accessibility for various groups of city residents (low-income households, unemployed individuals, seniors (age 60+), children (age 0-14), women (for comparison, men as well). To achieve this goal, we combined datasets of UPTS in Bratislava with the pedestrian communication network and identified an effective service area for which we subsequently determined the sizes of the respective population groups of residents. Finally, we verified the functionality of the entire UPTS model by measuring the accessibility of the selected destination, Ruzinov Hospital. Our results could be summarized as follows: The functioning of UPTS is very similar during the morning rush, evening, average working day (Monday to Friday), and weekend - Sunday. During these time periods, approximately the same main lines operate, and there is a higher utilization of the same transfer points. The difference lies mainly in the frequency of departures of specific lines. During the night, the system operates based on different lines compared to the daytime, with transfers possible only at one central point/corridor. This fact also affects the usability and accessibility of UPTS, reflected in the accessibility of Ruzinov Hospital, which is very limited during the nighttime period. However, the accessibility of the hospital by UPTS is higher for the unemployed residents, low-income individuals, and children than the overall residents average, which is also reflected in the distribution of women. A negative aspect is that UPTS is less accessible for seniors. It must be said that this fact varies significantly in the heterogeneous spatial layout of the city. This was confirmed in our measurement of the accessibility to Ruzinov Hospital, where seniors have roughly the same level of accessibility as the overall residents average.