Types and retroreflective classes of roadworks signage
The effectiveness of temporary signalling devices depends on their immediate visibility in all weather and lighting conditions. Signs fall into warning, regulatory and informatory categories, but the decisive technical element for type approval is the film applied to the metal backing. For sites in built-up areas, on urban roads with speed limits below 50 km/h, signs with Class 1 film (Engineer Grade) are required. On rural roads, motorways and in all high-speed traffic situations, the regulations require Class 2 film (High Intensity or microprismatic). The latter provides far superior retroreflection, allowing the message to be perceived from long distances or in fog. Metal backings must also feature safety-folded perimeter edges, essential to prevent cuts to operators during installation and removal.























