As IKONOS satellite with 1m-resolution camera has been launched in 1999, mapping using space-borne images will be a hot issue in computer vision area as well as photogrammetry, mainly because most of major manmade objects of interest can be identifiable. One of the automatically identifiable objects of importance may be roads. Detecting roads using edge detection approaches may be very difficult because a number of edge elements from such as buildings, etc. can be generated from edge detector. In this paper, we propose a method for the extraction of approximated road regions based on region segmentation that utilizes region information. Our method consists of the following three steps. First, an image is segmented using the modified hierarchical multi-scale gradient watershed transformation. Then, the road candidates are identified using information about road – gray level, elongatedness and connectedness. The identified road candidates are expanded by connecting the close-by roads ...