Chapter 4 Traffic Control and Measure Equipment C. The methods of Data Collection (1 Digital Information: it is widely used information By loop detector. Infrared Detector, Ultrasonic Detector. Radar ② Image Information:Eve,Ⅴ ideo recorder Voice information: Radio, Telephone, Mobile Phone① Digital Information: it is widely used information. By Loop Detector, Infrared Detector, Ultrasonic Detector, Radar ③ Voice information: Radio, Telephone, Mobile Phone ② Image Information: Eye, Video Recorder c. The Methods of Data Collection Chapter 4 Traffic Control and Measure Equipment