Based on deep learning camera/radar object detection and tracking technology, the proposed road side unit (RSU) system has achieved over 95％ vehicle detection accuracy within 100m detection range in the processing performance of 20fps under nVidia Jetson Xavier platform. Compared to the 32-beam lidar based RSU, the proposed RSU achieves 97％ reduction of sensor cost that exhibits high competitiveness in deployment cost. The proposed RSU system has been verified in fields and we are now cooperating with an industry partner to deploy the RSU system in both Tainan and Tao-Yuan cities.