This document provides design guidelines, test procedure references, and performance requirements for red and yellow overhead warning devices on school bus vehicles which are used to alert traffic to stop when passengers are loading and unloading.
Manufacturers are now integrating flashers into the lamp. Environmental tests for flash rate have been added.
Added references to FMVSS108, CMVSS108, SAE J387 terminology, and SAE J1330 laboratory accuracy guidelines.
Added reference to SAE J578. This was added to ensure consistency with other SAE lighting documents.
Added definitions for: Light source, Light Pulse, Optical Element, Optical Power, and flash.