This report investigated the effects of using speed-reducing devices e.g. humps, central and dividing islands and chicanes, on heavily-trafficked streets. Three streets were chosen in three separate swedish cities. Two of the streets showed a 10% reduction in traffic volumes while the third showed a slight increase (although a street parallel to it showed a 20% increase over the same period). speed was reduced on all three streets while fuel consumption increased. There were some additional maintenance costs on two of the streets e.g. damaged traffic signs, curbstones and chicanes. Overall the speed-reducing devices used had a considerable effect on traffic safety, conflicts being reduced by 40% on one street and 70% on another. The third street did experience some conflicts at crossings. After the studies had been carried out however, in the case of two of the streets, negative public reaction and (in one case) the influence of a public transport company, caused the speed-reducing devices to be removed.
Abstract