A road in Beaconsfield exemplifies one of the problems with speed humps. It has 30mph limit but speed humps mean 20mph is more realistic. However, by driving at a constant speed of 20mph, people roar past you between each hump, somewhat counterproductive to traffic calming.
Similarly, speed humps are not always continuous across the road, encouraging people to drive at each other in the centre of the road to avoid the humps.
Jeffrey Smith (M), 4 Baden Drive, Horley, Surrey, RH6 8SD