We have school zones where drivers must reduce speed to 40kph, usually from 60, but only during certain hours before and after school. If you get it wrong even by 5 minutes the fine is a hefty one and P plate drivers get an automatic licence suspension of 3 months. Most of the signs have now been fitted with small solar panels so that the sign is ringed red lights whenever drivers must reduce speed. This is a big improvement both for road safety and for the drivers' hip pockets.