Transport for NSW: New bus technical specifications - New requirements (TS150) for warning signs and flashing lights on school buses to apply from February 2019. This is based on the Heavy Vehicle (Vehicle Standards) National Regulation.

Comment
: In 1995 Dr Alec Fisher and I conducted a review of school bus warning systems. (ESV paper) One of the main conclusions was that the yellow turn signals being used on school buses at the time were woefully inadequate for traffic on  high-speed roads on bright days, when their typical signal range was around 50 metres. We recommended much brighter lights be used and showed that the lights in use on school buses in the USA were suitable. Nothing changed! Tasmania introduced bright lights on its school buses in 1996. The Draft National Heavy Vehicle Inspection Manual, pubished by the NRTC in 2001, had this note: "Note: for optimum signal range in bright daylight the on-axis intensity is required to be no less than 1500cd. This is about six times brighter than typical turn signals." Several Australian States and Territories picked up these requirements, which were then included in the National Regulations.

So... after 30 years our research has become law in NSW.