This SAE Recommended Practice applies to retroreflective sheeting materials that are used on truck tractors and trailers 2032 mm or more in overall width and with a gross vehicle weight rating (GVWR) over 4536 kg and school buses to improve vehicle conspicuity. The retroreflective sheeting materials for the truck tractors and trailers are super-high-intensity materials containing microprisms. The retroreflective sheeting materials for school buses may contain flexible non-exposed glass bead lenses or microprisms.