The number of electric vehicles (EV) is increasing rapidly, and it is not yet sure how the grid infrastructure will be built, and how this will affect the power system. One option for charging EVs is a dynamic wireless power transfer (DWPT) system, where EVs can charge while driving. This paper presents a methodology for modelling the load from an electric road with a DWPT system and the load from households in an area. A case study for a specific highway section in Norway is also conducted, illustrating the methodology for one substation. The case study shows that the peak loads from the households and the electric road occur at different times both during the year and day. In year 2050, the peak load from the electric road could reach over 6 MW, based on numbers from the Norwegian National Transport Plan. The results from this paper will be of aid in long-term grid planning when considering electric roads in areas with existing load, hence ensuring a socio-economic planning and operation of the power system.