车辆检测可以采用埋地线圈检测、红外检测、雷达检测、视频检测等多种方式。采用视频检测可以避免破坏路面、不必附加外部检测设备、不需矫正触发位置、节省开支，而且更适合移动式、便携式应用的要求。
Vehicle detection can be realized by buried coil detection, infrared detection, radar detection, video detection and other methods. Using video detection can avoid damaging the road surface, without additional external detection equipment, without correction of trigger location, saving costs, and more suitable for mobile and portable applications.
具备视频车辆检测功能的牌照识别系统，首先对视频信号中的一帧(场)的信号进行图像采集，数字化，得到对应的数字图像；然后对其进行分析，判断其中是否有车辆；若认为有车辆通行，则进入到下一步进行牌照识别；否则继续采集视频信号，进行处理。
For the license plate recognition system with video vehicle detection function, firstly, image acquisition and digitization are carried out for a frame (field) signal in the video signal to obtain the corresponding digital image; then, analysis is carried out to determine whether there are vehicles in it; if there are vehicles passing through, then proceed to the next step for license plate recognition; otherwise, continue to collect video signal for processing.