Abstract: A device for displaying and recording the speed of motor vehicles suitable for application to the front and rear bumpers of automobiles is described, consisting of an indicator 1 whose movement is dependent on the speed of the vehicle and which activates internal and external visual and/or acoustic alarm signals whenever the maximum speed limit is exceeded; said indicator also consisting of a triangular-sectioned thread that causes a slit or groove to be made on a sheet 4 of soft plastic for the ascertainment of speed at the moment of collision or accident; and a cable 10 for laterally connecting the front and rear boxes 7 and 7' providing the ascertainment in case of eventual lateral collision.