The traffic problems on main roads passing through town and village centres are mainly caused by traffic passing without consideration to inhabitants and local traffic, with speed considerably higher than the limit. This has led to many accidents, large problems with risk perception, environmental problems and a great local interest for improvements. The Danish Road Directorate decided to implement traffic calming schemes in several Danish towns which were appropriate to the towns and the defined problems, also including economy. The traffic calming schemes should be effective, the visual appearance satisfactory and the measures should adapt to the local urban and traffic environment. Safety should be improved and the number of accidents reduced. COWI has assisted the Danish Road Directorate with the evaluation of the traffic calming schemes in 21 towns. This paper presents the results of a before-and-after study of traffic calming schemes in Denmark. The general result of the traffic calming schemes was a reduction in the average traffic speed by 10 km/h. In towns with new roundabouts the average speed was reduced by 15 km/h. In some towns the average speed was reduced by 30-40% (17-26 km/h). Reduction in traffic speed by each of the different means (e.g. gateways, roundabouts including miniroundabouts, pedestrian refuges and central refuge islands for narrowing the carriageway, chicanes, road humps, including flat topped humps) is also presented in the paper. The paper concludes that by investing approximately 0.3 0.4 mill. £ per km in small urban areas, positive effects can be obtained on traffic safety, risk perception, and the environmental quality of the area. Transactions on the Built Environment vol 33, © 1998 WIT Press, www.witpress.com, ISSN 1743-3509