324,828. Jackson, L. Mellersh-, (Siemens & Halske Akt.-Ges.). Feb. 14, 1929. Road signals. - Advertising signs c are automatically switched on during the halt period, or the halt and caution periods, of a traffic-control station having lamps a. In a modification, Fig. 3, the box d has two continuously illuminated advertisement surfaces, and at each switching over of the signal lamps from red to white or green, or at each reverse switching, the box is rotated through 90‹ by an electromagnet i actuating a pawl h engaging a pin-wheel g on the shaft f of the box. When the control station is not functioning a switch automatically switches on the advertisements for the required period.