A control system for an autonomous vehicle is disclosed. The control system may receive information that identifies distances, measured by a sensor of the autonomous vehicle, to different points of a roadway. The control system may generate a representation of a curve based on the information that identifies the distances. The representation of the curve may include a series of points that represent a curvature of the roadway. The control system may identify a point, of the series of points, that satisfies a condition based on the representation of the curve. The control system may store, in the memory, an indication that the point is a center point of the roadway.