The device automatically actuates the vehicle emergency lights when the brake pedal and one of the turn signals are simultaneously used. To do so it uses an integrated circuit that actuates a periodic pulsating signal in its outputs when a continuous signal is received in its inputs that comes from the brake pedal switch, and, at the same time, a pulsating signal from one of the turn signals. The device is especially indicated for warning that a dangerous maneuver with left or right turns is going to be performed on two-way highways, for example.