This SAE Recommended Practice applies to retroreflective 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. The retroreflective materials for the truck tractors and trailers are super-high-intensity materials containing microprisms. The retroreflective materials for school buses may contain flexible non-exposed glass bead lens or microprisms.
1) Expand on the Coefficient of Retroreflection test methodology to specify that the material must meet requirements in all mounted orientations (must be specified per ASTM E810 otherwise it's the average of measurements at 0° and 90° which does not make sense in these applications). Allow final product trim sizes (50 mm wide x color segment lengths) to be tested instead of 200 mm x 200 mm sizes. 2) Add Nighttime Color requirements in line with ASTM D4956 with ASTM E811 test methodology 3) Change Test 1 and Test 2 weathering - D4956 already specifies a 36 month weathering with an optional interim 2000 hour Xenon exposure; require both weathering types to meet 80% of minima. 4) Clarify sample sizes for each test rather than stand-alone 5.1 Sample Preparation Test 5) Specify Dimensional Test requirements in line with FMVSS 108, 131, and 217 for 6.1 Dimension Requirement