This paper discusses the most attractive emission compliance options (emission abatement technologies and cleaner fuels) in intermodal transport chains that include short sea shipping. Most studies on emissions-based transport chain comparisons have estimated high levels of nitrogen and sulfur oxide emissions in maritime transportation, decreasing its competitiveness. However, the consequences of regulatory and technological developments and the integration of maritime transport in intermodal transport chains have not yet been considered in detail. In order to address this research gap, a numerical model for computing emissions from different transport modes in an intermodal transport network, under the effect of these developments, is presented that is based on bottom–up emission factors that depend on the fuel type, engine type, and operational profile of each vehicle. Different emissions scenarios are chosen for specific unimodal and intermodal routes (short sea shipping-based) between Portugal and northwestern Europe. Conclusions are drawn on estimated values of air pollutant emissions and greenhouse emissions, in CO₂-eq per unit of cargo, in each scenario. These results allow the identification of the most environmentally friendly transport chains, thus supporting the development of adequate transport policies.

A novel methodology is developed for determining the characteristics of a cargo roll-on/roll-off (ro-ro) ship and the fleet size required for a given short sea shipping route. The ship and required fleet size to satisfy the transportation demand (for each pair of speed and freight rate) are determined using a database of existing cargo ro-ro ships to obtain the main technical characteristics of the most suitable ship. The time charter, voyage costs and revenue are then calculated considering the technical characteristics of each ship. Fuel costs are corrected for the actual ship speed and loading condition. A number of restrictions in the transportation problem are considered leading to the exclusion of unfeasible solutions. The maximum profit over the period of a year is identified among the feasible pairs of speed and freight rate. This general methodology is applied in a case study that considers the route between Leixões (Portugal) and Rotterdam (Netherlands). The study allows the identification of the most suitable ship and fleet sizes for different market penetration levels and quantifies the impact on shipping company profit of changes in parameters such as fuel costs, time charter costs, emission control area, installed propulsion power and stacking factor.

This paper develops a methodology to estimate ship emissions using Automatic Identification System data (AIS). The methodology includes methods for AIS message decoding and ship emission estimation based on the ship’s technical and operational characteristics. A novel approach for ship type identification based on the visited port terminal is described. The methodology is implemented in a computational tool, SEA (Ship Emission Assessment). First, the accuracy of the method for ship type identification is assessed and then the methodology is validated by comparing its predictions with those of two other methodologies. The tool is applied to three case studies using AIS data of maritime traffic along the Portuguese coast and in the port of Lisbon for one month. The first case study compares the estimated emissions of a ferry and a cruise ship, with the ferry emitting much less than the cruise ship. The second case study estimates the geographical distribution of emissions in the port of Lisbon, with terminals corresponding to areas with a heavier concentration of exhaust emissions. The third case study focuses on the emissions from a container ship sailing along the continental coast of Portugal, differing considerably from port traffic since it operates exclusively in cruising mode.

This paper applies a methodology for computing external costs in an intermodal transport network that includes short sea shipping to explore the impact of external costs in its competitiveness. The network, which includes roads, freight railways, maritime and inland waterway connections, considers the specific characteristics of different transport alternatives and vehicle types, providing a fair comparison of the various modes. A case study focused on freight transportation between Northern Portugal and 75 destinations (NUTS2 regions) in north-western Europe is presented. The potential of different intermodal routes that include short sea shipping is assessed, including not only internal costs and times but also external costs per mode and unit of cargo. The impact of the different cost approaches in each country of transit is shown along with the progress that has been made in the integration of external costs, using the most recent EU estimates on marginal costs coverage ratios per country for freight transport modes. The results support the modal shift from road to sea in this corridor, providing means for modal comparison and for the development of short sea shipping’s image as a sustainable mode of transportation.