LED blank out DOT road signs. Our LED changeable message signs (CMS) are ideal for traffic control on roadways, bridges, tunnels and tollways. DOT blank-out signs feature a rugged NEMA 4X style/IP66 rated cabinet construction with custom or MUTCD compliant symbols laid out in LEDs. Messages blank out or extinguish when deactivated. LEDs are rated for 100,000 hours of continual life making our signs virtually maintenance free.