Embodiments of the present invention provide a method of determining a location at which a lane divider marking changes type, comprising determining (350) a first type of lane divider (120) marking based upon a frequency spectrum determined by Fourier analysis of first image data (431) corresponding to a first area, determining (350) a second type of lane divider (130) marking based upon a frequency spectrum determined by Fourier analysis of second image data (432) corresponding to a second area, and determining (360) a geographic location at which the lane divider marking changes type according to a comparison of the first and second types (120, 130) of lane divider marking.