A system and method for generating a road network based on satellite imagery. Plural pixels corresponding to satellite imagery of a region are obtained. For each of the plural pixels, a probability value corresponding to the probability that the pixel belongs within the road network is calculated. A grayscale image is formed based on the calculated probability values. Plural curves are produced based on the grayscale image, wherein the producing of each curve includes positioning a shape on the grayscale image so that an average intensity of the grayscale image covered by the shape exceeds a preset threshold, moving the shape about the grayscale image while the average intensity is maintained, and tracking the movement of the shape to produce the curve. A planar-connected graph is generated by connecting at least portions of the plural curves. The planar-connected graph corresponds to the road network.