Tunnels traffic signs are installed in the interior or entrance of the tunnel. The signs are produced in compliance with European standard EN12966. Modular design ensures simple maintenance by simple replacements of the parts. LEDs with high luminous intensity and long life time. Special system to protect LEDs from temperature peeks that might happen during device operation. Possible brightness control: manual brightness control, brightness control according to actual day time using precise algorithm, brightness control according to external illumination measured by 1 or 2 light sensors and external brightness control. Communication interfaces: RS232, RS485, Ethernet, Wi-Fi, GSM/GPRS.