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.
The Heavy Duty Lighting Committee has completed the five year review of this document and has made the following changes.
1. Retroreflective materials used for conspicuity on school buses has been clarified to better indicate their application. The red and white material specifications have been specifed for use on the school bus stop signal arms per FMVSS-131 and the yellow material has been specified for use as conspicuity treatment on school bus bodies per FMVSS-217.
2. Paragraph 4.1 was changed to add the equivalent FMVSS certifications for conspicuity materials.
3. Paragraph 4.2 was changed to remove the word "may" and add the word "shall" thus requiring the material to be marked with the certification designation letters.
4. Editorial changes were made for clarification.