A method (100, 200) for determining a map position of an ego-vehicle having a velocity, the ego-vehicle having a geographical position including a set of geographical coordinates and having an orientation, wherein said set of geographical coordinates and said orientation are determined by a localization system of a control system of the ego-vehicle, said method comprising: acquiring map data comprising a road geometry of a surrounding environment of the ego-vehicle; initializing at least one dynamic landmark, by: detecting and selecting a surrounding vehicle in the surrounding environment of the ego-vehicle based on one or more predefined selection criteria, using a vehicle perception system comprising at least one sensor; measuring a first position and velocity, relative to the ego-vehicle, of the selected surrounding vehicle located in the surrounding environment of the ego-vehicle, using the vehicle perception system; determining a first map position of the surrounding vehicle based on the measured first relative position of the selected surrounding vehicle and the geographical position of the ego-vehicle; predicting a second map position of the selected surrounding vehicle based on the determined first map position of the selected surrounding vehicle, the measured velocity of the selected surrounding vehicle, and the road geometry; measuring a second position, relative to the ego-vehicle, of the selected surrounding vehicle, at a point in time when the selected surrounding vehicle is estimated to be at the second map position, using the vehicle perception system of the ego-vehicle; and updating the geographical position of the ego-vehicle based on the predicted second map position of the selected surrounding vehicle and the measured second relative position of the selected surrounding vehicle, wherein said one or more predefined selection criteria comprises at least one of: the velocity of the surrounding vehicle is V ± 10%, where V is the velocity of the ego-vehicle; or a traveling direction of the surrounding vehicle is substantially the same as the ego-vehicle. acquiring map data comprising a road geometry of a surrounding environment of the ego-vehicle; initializing at least one dynamic landmark, by: detecting and selecting a surrounding vehicle in the surrounding environment of the ego-vehicle based on one or more predefined selection criteria, using a vehicle perception system comprising at least one sensor; measuring a first position and velocity, relative to the ego-vehicle, of the selected surrounding vehicle located in the surrounding environment of the ego-vehicle, using the vehicle perception system; determining a first map position of the surrounding vehicle based on the measured first relative position of the selected surrounding vehicle and the geographical position of the ego-vehicle; detecting and selecting a surrounding vehicle in the surrounding environment of the ego-vehicle based on one or more predefined selection criteria, using a vehicle perception system comprising at least one sensor; measuring a first position and velocity, relative to the ego-vehicle, of the selected surrounding vehicle located in the surrounding environment of the ego-vehicle, using the vehicle perception system; determining a first map position of the surrounding vehicle based on the measured first relative position of the selected surrounding vehicle and the geographical position of the ego-vehicle; predicting a second map position of the selected surrounding vehicle based on the determined first map position of the selected surrounding vehicle, the measured velocity of the selected surrounding vehicle, and the road geometry; measuring a second position, relative to the ego-vehicle, of the selected surrounding vehicle, at a point in time when the selected surrounding vehicle is estimated to be at the second map position, using the vehicle perception system of the ego-vehicle; and updating the geographical position of the ego-vehicle based on the predicted second map position of the selected surrounding vehicle and the measured second relative position of the selected surrounding vehicle, wherein said one or more predefined selection criteria comprises at least one of: the velocity of the surrounding vehicle is V ± 10%, where V is the velocity of the ego-vehicle; or a traveling direction of the surrounding vehicle is substantially the same as the ego-vehicle. the velocity of the surrounding vehicle is V ± 10%, where V is the velocity of the ego-vehicle; or a traveling direction of the surrounding vehicle is substantially the same as the ego-vehicle.