Examining the accessibility of public transport stops: The case of Istanbul

Reasons such as population growth, capital-centered urban growth, increase in automobile ownership and automobile-oriented transportation infrastructure cause many problems such as traffic congestion, air pollution, noise pollution and traffic accidents in cities. These transportation problems also restrict people's accessibility between two points in the urban space. In this direction, the city administrations, which adopt the sustainable transportation approach, switch to a movement-based perspective instead of automobile-oriented macro transportation solutions while preparing their transportation master plans. Thus, it is aimed to produce transportation plans focused on people, society and space. In this framework, for the public interest, it has become one of the main objectives of the transportation master plans to develop public transportation systems that contribute to social equality by addressing all segments of society and significantly reducing traffic density. The main priority of creating a sustainable public transportation system people can use comfortably is to ensure people's accessibility to public transportation stops. Regarding sustainable transportation planning, providing people access to public transportation stops in urban spaces is very important for urban mobility and social equality. Making public transportation stops accessible with an integrated approach will increase passenger demands for public transportation systems while reducing traffic density, private automobile demand and carbon emissions. In this context, the study's main aim is to examine the accessibility of public transportation stops in Istanbul. Accessibility measurements of public transport stops were analysed using the Service Areas Analysis tool offered in the Spatial Network Analysis extension of ArcGIS program, which is a Geographical Information System-based software. Within a five-minute walking distance, the population ratio that can reach the stops of the rubber-tyred public transportation types, which is one of the public transportation types, to the total population has been calculated as approximately 90%. On the other hand, the ratio of the population that can reach the rail system stations and sea transportation piers within a five-minute walking distance to the total population is approximately 3%. Even these two rates alone indicate that the Istanbul public transportation system is not sustainable. In addition, the findings of the study emphasize that the standards regarding the distances between public transport stops in Istanbul and the urban slope greatly affect the access to social services (such as stops and hospitals), and that these services should be located at certain standard intervals and as a result of service analysis. Due to the limited pedestrian access to the stops of the rail system and sea transportation types, there are suggestions for the need to invest more in these types of public transportation and to develop transfer opportunities so that passengers can use the public transportation systems holistically.