Abstract
Despite the ongoing processes of territorial integration, especially in Europe, there are still borders that fulfil their original function, namely that of a barrier. In some cases, this function has even been strengthened. Such is the case with Poland’s eastern border, which is also the external border of the EU and of the Schengen Area. This article presents the modal split of passenger traffic under conditions of frequent changes in the functions and permeability of borders, against the background of the key drivers behind the volumes of border traffic, i.e. the geopolitical, socio-economic, and infrastructural factors, both in relation to road, rail and border infrastructure. All sections of the border display some marginalisation of railway transport. The Polish eastern border is characterised by a sustained high share of bus transport, which pertains to all sections under analysis. The long waiting times for clearance when travelling in private cars was probably one of the factors behind the creation of the market for collective transport. Private transport is most dominant on the Polish-Russian border, while the largest share of crossings by bus is recorded on the Belarusian border.