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This paper discusses the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examines the case of Belgium as a testing ground. These policies consist in subsidizing intermodal transport operations (such as in Belgium, to stimulate rail transport), internalizing external costs (as recommended by the European Union in order to foster cleaner modes), and adopting a system perspective when optimizing the location of inland intermodal terminals. The study proposes an innovative mixed integer intermodal freight location-allocation model based on hub-location theory and deals with non-linear transport costs in order to replicate economies of distance. Our analysis suggests that subsidizing has a significant impact on the volumes transported by intermodal transport, and, to a lesser extent, that optimizing terminal location increases the competitiveness of intermodal transport. On the other hand, according to our assumptions, internalizing external costs can negatively impact the promotion of intermodality. This finding indicates that innovative last-mile transports are needed in order to reduce the external impacts of drayage operations.

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In this paper, we present a complex network analysis of the air transport network using the air cargo, instead of the passenger, perspective. To the best of our knowledge, this is the first work where a global cargo network comprising passenger airlines, full-cargo airlines, and integrators' capacity was studied. We used estimated yearly cargo capacity between airport pairs as input to the model. After assessing network characteristics of the sub-networks representing different carrier types, the full network was obtained as a super-imposition of the individual sub-networks. The resulting network has both small-world and scale-free characteristics. Its topological properties resulted in a higher flow imbalance and concentration with respect to its passenger counterpart, with a smaller characteristic path length and diameter. This result is consistent with the larger catchment area of cargo airports, which heavily rely on road feeder services for the ground leg. Finally, we showed how different attack strategies result in hubs of hub-and-spoke systems or airports behaving as bridges between communities being attacked first. We believe this work to be of relevance both for academics and for practitioners in an era where, due to the soaring of e-commerce and next day delivery, new players are entering the air cargo business and competition is constantly increasing.

The traditional approach to the road network design problem focuses on the optimization of the network efficiency under a given budget. Generally, this leads to the improvement of roads next to the largest population centers, where travel demand is higher. Such implications are not consistent with sustainable development principles since this will tend to increase the dissimilarities between large and small centers' welfare. Notwithstanding this, equity issues were rarely taken into account in road network design. Moreover, all existing studies rely on a single equity measure. In this paper we propose a brief review of equity concerns in transportation planning and present a comparison of alternative equity measures. We selected three different equity measures and incorporated them into an accessibility-maximization road network design model. The three equity measures considered reflect different perspectives on equity: the accessibility to low-accessibility centers; the dispersion of accessibility values across all centers (Gini Coefficient); and the dispersion of accessibility values across all centers and across centers in the same region (Theil Index). The implications of adopting each one of these equity measures are illustrated through the application of the optimization model to three random networks.