This article contains results of studies on the applicability of data from Intelligent Transportation Systems (ITS) for the purposes of geographical studies regarding the spatial mobility of inhabitants within a big city. The article focuses on the option of applying two types of sub-systems – induction loops and automatic number-plate recognition (ANPR) – and includes examples of analyses based on the resulting data, which can serve as a basis for mobility studies. The area on the example of which the capabilities of application of ITS data have been presented is Lodz – a large city in central Poland. The conducted research shows that ITS systems offer an enormous potential in providing data for spatial mobility studies. In order to fully exploit its worth, however, it is imperative to expand the research procedure by including, for instance, the results of qualitative research. Also, the interpretation of results obtained on the basis of ITS data ought to be performed with an awareness of numerous significant preliminary and simplifying assumptions.