Reduction of speed limit at Beeslack

I see that the council are proposing to cut the speed limit outside Beeslack high school at certain times. I can't help feeling that this sounds like a waste of time, unless they have some way to enforce it The article here says that there are successful 20mph speed limits in Dalkeith and Gorebridge but the ones I've seen have had massive speed bumps which force drivers to slow down. http://www.midlothianadvertiser.co.uk/news/local-headlines/speed_limit_cut_outside_penicuik_school_1_2017328