The standards applicable to microprismatic sheeting in the EU are discussed. Only Belgium, Germany, France and Spain have introduced technical specifications for microprismatic sheeting as Class 3 material and only these countries can make use of the sheeting mandatory. The requirements for such sheeting to be used in traffic signs are outlined with reference to the characteristics of vehicle headlamps. Luminance levels required for legibility are discussed, with high performance retroreflective materials required to meet the highest luminance class needed for continuous traffic in urban areas and interurban motorways and main roads. The calculation of retroreflective properties is described. Signs are assumed to require three seconds for full recognition. The influence of the positioning of signs on their luminance is explained. For the covering abstract see ITRD E123380.
Samenvatting