Where I live, they have some speed humps in the road. Damn stupid things - many drivers (especially taxi drivers) drive fast and then brake just before the speed humps. Drivers of small vans just ignore them completely. So, what's the point?
This report in The Observer says that it's much better to replace speed humps with more subtle traffic calming:
A major report for the Department for Transport reveals that 'psychological' traffic calming works. Painting the road different colours, taking out white lines or planting things in the way of sight-lines on corners can be used to make roads look narrower, or bumpy or windy. Drivers then feel less safe and drive more slowly - a principle adopted most radically in one town in the Netherlands which abolished all signs and road markings.
The four-year study by the Transport Research Laboratory found that many optical tricks were successful in slowing speeds: in simulator tests all speeds fell when the measures were introduced, some by an average of more than 4mph; and in one test in Latton, Norfolk, average speeds fell by up to 8 mph, and the speeds of faster drivers by even more.
The most successful measures, likely to be used in future, were using red bricks to make the road look narrower and small areas 'built out' into the road with trees, shrubs or wooden posts, said the report
My first reaction is that I don't understand why it needed a four-year study to reach these obvious conclusions. Speed humps are largely ineffective because many drivers see them as a challenge - how quickly can they accelerate away from one speed hump and how late can they brake before the next one. Perhaps they enjoy an uncomfortable ride, and don't pay for their own petrol, or perhaps they're just stupid. Who knows?
If you can fool a driver into slowing down, he won't even realize that this is happening, and will almost certainly drive at a steady speed, which is safer and more economical.
Less cheese and more driving, and soon this blog will be worth as much as Fumier.