Infrastructure elements are a crucial factor in accommodating larger ships, organizing longer trains, and ensuring the higher flow of goods in intermodal hubs. The Belt and Road Initiative (BRI) supports the development of infrastructure on the defined transport routes—the Maritime Silk Road (MSR), which includes the European southern transport route through the northern Adriatic. The research emphasizes the importance of the port, and railway infrastructure development on the Baltic–Adriatic Corridor (BAC) by analyzing the pollution level produced from transport means currently employed. The results of SO2, NOx, PM10, and the energy efficiency of intermodal transport chains prove that the current transport route to the northern leg of the BAC via the port of Gdansk is more environmentally friendly, even if it is about 3000 NM longer. The article provides a scientific contribution by pollution data elaboration for demonstrating the need and justification for high investment in BAC in order to establish sustainable transport chains. The study shows that pollution values from supply chains on the Asia–Central Europe axis could be reduced by up to 30% by eliminating infrastructural barriers in the port of Koper and on the railway network at BAC, which is one of the primary goals of BRI.