The system includes a stop sign device, a wave signal transmitter, a signal receiver and a warning signal. The wave signal transmitter is located at the stop sign device, that is it is near it, or is attached to it. The transmitter projects a wave signal outwardly in a direction from the front of the stop sign device, that is toward oncoming traffic that is expected to comply with the stop sign device. The wave signal of the transmitter has a predetermined frequency and transmission strength, and may be radio or IR or other wave signal. The signal receiver is adapted to receive a wave signal of the same frequency of said wave signal of the transmitter, so that when it is near the transmitter, it will receive that signal. The warning signal is a signaling device that is connected to the signal receiver and is adapted to operate when the signal receiver receives a signal from the wave signal transmitter, and will continue to signal a warning until the transmitter is passed or the system is shut down by an operator override.