A traffic environment recognition system includes an image-processing unit, an information-merging unit, a radar unit, and a network connected to the image-processing unit, the radar unit, the information-merging unit and a vehicle control unit capable of controlling the traveling operation of a host vehicle. The image-processing unit recognizes headway distance, the azimuth, relative speed and width of the preceding vehicle, and the position of the host vehicle in a lane. 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 and the radar unit through the network, merges the recognition results, identifies recognition objects relating to the recognition results. When a vehicle relating to the recognition results provided by the image-processing unit and a vehicle relating to the recognition results provided by the radar unit are one and the same vehicle, the information-merging unit produces output information by adding a sensor information indicating that the vehicles are one and the same vehicle to the recognition results, and sends the output information through the network to the vehicle control unit.