Recently, vehicles adopt the whistling system to attract other drivers' attention, however, whistling can cause great harm to the environment and human health. To eliminate the noise pollution, we have designed a new warning system-SVM. Due to the need of low-cost precise positioning in the three-dimensional space in SVM system, we have designed the Phase Difference Location (PDL) system, which combines the GPS system and the phase difference algorithm to achieve centimeter-level positioning. Thus, we have designed the Intelligent Hazard Pre-prediction (IHP) system, which combines the Vehicles Trajectory Prediction (VTP) algorithm with the Hazard Detection algorithm to determine whether the target vehicle should send the alert signals. The Hazard Pre-prediction (IHP) system, Phase Difference Location (PDL) system, wireless communication, and infrastructure components constitute the SVM system — vehicles' silent alert system.