Despite the political objective of decreasing road transport and transfer cargo to road and sea, short sea shipping is struggling. There is therefore a need for development of new short sea Ro-Ro vessels which use significantly less fuel per ton transported which can be built at a modest cost. This feasibility study has: First mapped the main characteristics of the current fleet, i.e. dimensions, capacities, installed power and designs speeds; Second investigated alternative combinations of main measurements to enable more slender hull forms which require less power and hence give fuel consumption and fuel cost per transported unit; Third, performed a case study to compare the economic and environmental performance of these slenderer designs, with traditional designs and road only solutions. This study shows the advantage of investigating a large number of alternative dimensions and capacities to identify the designs which reduces cost and fuel consumption. And that the best option is to design and build more slender vessels.