This article analyzes the opportunities of the Chinese initiative “One Belt, One Road”, for the development of the Baltic Sea macro-region (BSR), as a single transport cluster. One of the objectives of the initiative is to strengthen transport linkages from the Pacific Ocean to the Baltic Sea Region. Thus, the contemporary macro-regional approach to the development of EU macro-regions can provide an additional impulse to the creation of formal macro-regional inter-cooperation, via in this case, the project that will advance the transport infrastructure of the region. This study examines the situation of the railway sector in the BSR in the period 2004–2015, through hierarchical cluster analysis, to identify countries with similar trends in cargo flow turnover. Taking into account the favorable geographical position of Poland, its transport performance and advanced (in comparison to other Baltic Sea region countries) relations with China, it is concluded that Poland’s conditions are more suitable to promote economic integration with its closest neighbors – the Baltic countries- through the creation of formal macro-regional railway transport within the Rail Baltic project.