Since the beginning of 2015, the International Maritime Organisation has introduced Sulphur Emission Control Areas (SECAs) to limit the sulphur content of bunker oil. As the price of the low sulphur marine fuel has constantly been higher than that of the heavy fuel oil, this change was expected to increase the cost of sea transport. As such, this would make sea transport less competitive against other transport modes in cases where other modes of transport would realistically be applicable. This research analyses the backshift effect of the SECA regulation in the Baltic Sea Ro-Ro traffic, where land based transport alternatives are available. The findings indicate, that the transport flows are sensitive to changes in cost balance between sea and road transport. However, due to the decline of crude oil and marine fuel prices, no major changes between road and sea transport have occurred.