Following your letters on speed cushions I have a similar tale. I have owned from new an X-Type Jaguar 2.2 Diesel, now 2 years old. Last month I took it in for its annual service. All ok except that the inside edge on both front tyres were worn to a point of being illegal. These tyres had only done 12,400 miles, tyre pressures regularly checked and balancing and tracking checked. Having to pay out £220 for new tyres didn't go down well as the rest of each of tyre still had good mileage left in them. The tyre guy said that wear was probably due to regularly going over speed cushions. Most of my travelling is through suburban areas both to and from work and in the course of undertaking my job. My journey each way encounters 10 humps on one road alone. An office I have to travel to has 25 humps on one stretch of road, all close together. Birmingham like a lot of areas receives grants from the government for neighbourhood renewal schemes. This money seems to have funded a lot of these road calming schemes around the city and many side roads have blossomed with these humps. Silly really as many of these roads are full of parked cars and you can' t drive very quickly down them anyway. Tables and pinch points in the road seem to be the better solutions and in the long run more cost effective to maintain because of their longevity. Like you, I wonder about the overall effectiveness of these humps. I just hope that there is a major rethink on this subject as money spent on these schemes are short term problem solvers but major revenue budgets will be required in the future to maintain them.