BSM systems use high-tech sensors and side-mounted cameras that connect to a vehicle’s main computer. The sensors and cameras monitor adjoining lanes for approaching traffic, and when they sense an advancing vehicle, the system goes into a warning mode. However, some BSM systems engage only when the driver activates the turn signal, while others engage whenever the sensors and camera identify another vehicle in the blind spot. The alerts can include a sound, blinking light, or a vibration in the steering wheel, and the alert will keep going on until the other vehicle moves away or the driver turns off the turn signal.