Estimating the depth of the road scene is a key step for intelligent transportation and robot navigation. A depth estimation algorithm for single static road image is presented. The algorithm obtains a series of closed areas of the image based on the edge growing segmentation algorithm. The statistic characteristics of each region are computed, including color, area, position, straight lines, vertical lines, and parallel lines. Based on these characteristics, the road vanishing point is further estimated, and the sky, road and vertical regions are estimated. The depth of the road image is estimated by using vanishing point and the statistic characteristics. The experimental results show that the proposed algorithm can effectively estimate the road vanishing point, as well as the road depth information.