The authors propose a method for evaluating the public transport accessibility of a city, based on the spatial distribution of real estate and commercial property in its territory, it enables making a rating table of routes and stops. The relevance of the study is related to the high social importance of mass transit, since its accessibility creates a more comfortable urban environment and offers new opportunities to the residents. The significant growth of research on this topic is a result of the social need to improve the use of urban space. The rapid development in the field of big data processing makes it much more relevant to the real situation than any previous models. However, researchers often lack up-to-date information on the distribution of the population in a given territory, because the concept of state open spatial data in Russia is currently in its early stages, and city authorities may decide to make it confidential. The proposed quantitative approach to assessing the provision of urban areas with land transportation means is based on using spatial data available in open sources, as well as methods of geospatial analysis and modelling. It is used to study the public transport in St. Petersburg, RF; the technique has enabled identifying the main municipal routes as well as the parts of the city requiring network expansion