DEVELOPMENT OF TECHNICAL SUPPLY AND TEST CONDITIONS FOR TRANSLUCENT TRAFFIC SIGNS

UNTERSUCHUNGEN ZUR ENTWICKLUNG TECHNISCHER LIEFER- UND PRUEFBEDINGUNGEN FUER TRANSPARENTE VERKEHRSZEICHEN

A BASIC REQUIREMENT OF TRANSLUCENT TRAFFIC SIGNS IS UNIFORM DISTRIBUTION OF THE LUMINANCE OVER SURFACES OF SIMILAR COLOUR. THERE MUST BE A DEFINED VALUE OF LUMINANCE IN ORDER TO GUARANTEE GOOD PERCEPTIBILITY AND TO AVOID THE "BLACK HOLE". TRANSLUCENT MOTORWAY SIGNS ON SIGN BRIDGES ARE OFTEN TOO BRIGHT, AND A POTENTIAL CAUSE OF ACCIDENTS. RECOMMENDATIONS FOR EVALUATING ILLUMINATED TRAFFIC SIGNS EXIST IN STANDARD DIN 67521, SHEETS 1 AND 2, BUT PRACTICE SHOWS THAT THE TOLERANCES GIVEN THEREIN, FOR EXAMPLE FOR LUMINANCE, ARE OFTEN TOO GREAT, AND THAT THE UNIFORMITY OF THE LUMINANCE IS SOMETIMES INSUFFICIENT. THERE ARE NO CLEAR SPECIFICATIONS COVERING THE INSTALLATION AND ACCEPTANCE OF TRANSLUCENT TRAFFIC SIGNS, AND THIS RESULTS IN THE ARRANGEMENT OF THE LAMPS AND THE TYPE OF LIGHTING BEING MODIFIED SEVERAL TIMES AFTER INSTALLATIONS. SUPPLY AND TEST SPECIFICATIONS FOR TRANSLUCENT TRAFFIC SIGNS ARE TO BE DEVELOPED. SUPERSEDES IRRD RESEARCH PROJECT NO 39074.