A traffic environment recognition system includes units for image-processing and information-merging, a radar unit. A network is connected to the image-processing unit. The radar, information-merging, and a vehicle control unit control the traveling operation of the vehicle. The image-processing unit recognizes headway distance, the azimuth, relative speed and width of a preceding vehicle, and the lane position of the host vehicle. The radar unit recognizes headway distance, the azimuth and relative speed of the preceding vehicle. The information-merging unit receives recognition results provided by the image-processing unit. The radar unit through the network, merges and identifies those results. When the recognition results provided by the image-processing unit and the radar unit relate to the same vehicle, output information is produced by the information-merging unit to identify the vehicles as one and the same vehicle and sends the output information through the network to the vehicle control unit.