“Flashing lights in school zones have been found to slow motorists by an average of seven kilometres an hour.
“By the end of June this year there will be more than 820 flashing lights in NSW, covering more than 990 schools.
“This is more than a quarter of all schools in NSW.”
http://www.nswnationals.org.au/index.php/news/media-releases/308-next-round-of-flashing-lights-announced
"One quarter of all NSW schools."< but that leaves 3/4 of NSW schoolchildren without this proven way of slowing down cars near schools.
Yes it costs a lot of money, but it didn't have to
All NSW schools could have suitable flashing lights installed for the money that was spent on painting "dragon's teeth in school zone.
http://www.rta.nsw.gov.au/roadsafety/children/schoolroadsafety/dragons_teeth.html
.