While the technological development of vehicles and fuels is not adequate to meet current climate mitigation targets, infrastructure development also plays an important role in transforming the transport system. Previous studies have argued that conventional infrastructure planning is incapable of implementing climate mitigation. The aim of the paper is to provide insights into power means and mechanisms that counteract integration of climate mitigation targets in infrastructure planning. This is done by an in-depth case study of current Swedish national transport planning. This case provides a rich illustration of a situation with high political ambitions regarding climate mitigation on the one hand, and power mechanisms and resistance with regard to climate goals during the planning process on the other. The case is analysed using the perspective of power circuits and shows how forecasting works as an obligatory passage point, sorting in and out which analyses will be part of the decision-making material. Analyses which do not fit the forecasting model are dismissed from planning. The conclusion is that as long as the transport infrastructure planning practice is dependent on forecasting as the only central analysis there will be difficulties in changing the scope of infrastructure planning and making climate goals central for transport planning.