Ya, i especially like this passage;You might like to review this article, which has lots of statistics you can refer to on the matter:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1127572/
The Association of British Drivers has, however, warned about the dangers of allowing local authorities to set their own 20 mph limits. The association thinks that decisions about where to implement slower speed limits will be made on a political basis, resulting in inappropriate limits on some roads. Inappropriate limits, it argues, will mean that drivers will be more distracted as they focus their attention on the speedometer and not the road ahead.9 It has called for limits to be “reasonable, consistent and above all, based on sound, established road safety principles.”9
Certainly there is a danger in focusing solely on lower speed limits as a means of reducing accidents. Other factors that contribute to road related deaths and injuries include alcohol, tiredness, and poor driving skills. Traffic calming measures and education to improve driver behaviour5 are also an essential parts of road safety. Education should focus not only on drivers but also on parents and children.
So it not fact, just a lot of conjecture and a whole lot of optics.
Who mentioned school zone, not me.
As far as school zones are concerned most kids are brain dead and illogical, especially teenagers so something has to be done. Short of make big detours this was a reasonable modification.






