System for illuminating a carriageway in a case of fog

A system for illuminating a carriageway in a case of fog, comprising:

• a road safety barrier which is arranged along a carriageway;
• at least a fog density detecting device which is arranged along the road safety barrier;
• a plurality of light sources which are borne by the road safety barrier, which are distributed along the road safety barrier and which are orientated so as to each emit a light beam having a direction that is transversal to the extension axis of the road safety barrier;
• a control unit which is connected to the plurality of light sources and to the at least a fog density detecting device which is configured to activate the light sources of the plurality of light sources when the at least a fog density detecting device detects a fog density value of above a threshold value;
• wherein:
• the plurality of light sources are orientated so as to illuminate horizontal signage arranged on the carriageway;
• wherein the light beam is substantially collimated;
• the light beam has a first angular opening on a vertical plane and a second angular opening on a horizontal plane;
• the first angular opening is at most 30°;
• and
• the second angular opening is at most 100°.