Modal shift within the freight transport sector has been promoted by policy makers as one of the means to achieving climate and environmental targets for several decades. The European Union has also had modal split objectives in place since 2011. In the Green Deal the ambition of shifting freight away from road transports is repeated. Even though the literature on mode choice is well established, there is less consensus about the volume of freight with potential to shift and, more importantly, the actual contribution of modal shift to achieving environmental and climate objectives. Based on a literature review to determine the potential of freight modal shifts within different segments in Sweden, this paper discuss the underlying assumptions explaining how freight modal shift is interpreted both as a political means to achieving overarching policy objectives and as a policy objective in itself.