Recognizing preceding vehicles and measuring distance headway are very important technologies for advanced vehicle control such as collision avoidance systems and automated driving systems. Typical methods to realize these technologies are using a laser radar and an image processing. Those two methods have complemental characters. That is, distance data are easily obtained but recognition of vehicles are required various techniques by use of the laser radar, and to recognize vehicles is rather easy by use of image processing. We are developing a fusion system combined those characteristic properties of laser radar and image processing. This system recognizes preceding vehicle positions and measures distance data using the laser radar, and improves certainty of the recognition results. This paper presents a general structure of this fusion system, and algorithms for recognizing and chasing vehicles. Details about original fast tracking algorithms are described.