A traffic message signal device includes a housing having a display structure. The display structure includes a non-reflective support panel supporting a plurality of light-emitting diode elements arranged in a configuration defining a traffic-related message. The light-emitting diode elements are high...http://www.google.de/patents/US5136287?utm_source=gb-gplus-sharePatent US5136287 - Traffic-related message signal using light-emitting diodes
