Following the liberalisation of the railway infrastructure, the non-discriminatory approach to each railway undertaking is necessary, including the issue of the train paths provision in terms of the railway infrastructure capacity. Expression and provision of the throughput capacity of the railway network by absolute number of train paths appear to be inadequate and inaccurate at first glance. There are many ways of calculating the capacity of rail infrastructure, as well as several ways of expressing it. The paper describes the testing of the railway infrastructure capacity in a computer based simulation model, which provides results for further research in the area of this issue. Two hypotheses oriented towards the research on the linear dependence of capacity on the number of train paths as well as towards the need for capacity estimation for a whole track or for only one block section are tested.