One of the main concerns of the antitrust authorities and policy makers in the field of freight transport is the market concentration and competition level inside the IFT market (Gómez-Ibáñez & de Rus, 2006). An IFT market comprises of different IFT chains—which themselves include different actors providing different services (i.e., preand end-haulage, transshipment, and main-haulage). All these IFT chains, together, form an IFT network. Anticompetitive behavior of the IFT operators (e.g., vertical or horizontal integration) could increase the market concentration, and potentially reduce the welfare of the customers (Motta, 2004). In fact, antitrust authorities may scrutinize and limit such business practices because they could harm the competition level in the IFT market (Mazzeo & McDevitt, 2014). Accordingly, an economic analysis of the concentration and the market structure is needed. The analysis of the market structure and concentration measures for IFT service can be done at several different levels. First, the analysis can be performed for separate segments, for example, the market for transshipment service or the market for main-haulage service (see, e.g., Wiegmans et al., 1999; Makitalo, 2010; Lam et al., 2007; Sys, 2009; Merikas et al., 2014). However, due to the multistage characteristic of IFT service, the segmental analysis gives an incomplete view of the IFT market. In other words, the competition is between IFT chains or even between different corridors to transport the cargo from one “origin” to one “destination”; therefore, a network-based analysis is needed. To analyze the market structure for IFT service, the Intermodal Freight Transport Market Structure (IFTMS) model was developed in our previous study (Saeedi et al., 2017). IFTMS uses graph theory and defines distinct submarkets in an IFT network. These submarkets are represented as nodes (transshipments), links (main-haulages), and paths (corridors, and O-Ds) in the model. Each “corridor” may have multiple IFT chains that include a sequence of nodes and links from an origin to a destination. The IFT chains in a corridor are organized by different forwarders to deliver an integrated IFT service to the final customer. As distinctive submarkets inside an IFT network are defined, IFTMS applies a flow optimization model to assign the flow to the IFT network corridors, and then to the respective chains, links, and nodes. Next, the concentration indices— like concentration ratio (CR) or Herfindahl-Hirschman Index (HHI) (OECD, 1990)—for these IFT submarkets are calculated. Further details on the IFTMS model can be found in Appendix E and Saeedi et al. (2017).