A method is provided for detecting road-side edges in a road segment using a light-based sensing system. Input range data is captured using the light-based sensing system. An elevation-based road segment is generated based on the captured input range data. The elevation-based road segment is processed by filtering techniques to identify the road segment candidate region and by pattern recognition techniques to determine whether the candidate region is a road segment. The input range data is also projected onto the ground plane for further validation. The line representation of the projected points are identified. The line representation of the candidate regions is compared to a simple road/road-edge model in the top-down view to determine whether the candidate region is a road segment with its edges. The proposed method provides fast processing speeds and reliable detection performance for both road and road-side edges simultaneously in the captured range data.