This paper describes the development of Traffic Calming Facilities in Ireland since 1993. In 1999 the National Roads Authority published its Guidelines on Traffic calming for towns and villages on National Routes (1). This guideline describes the main elements of traffic calming using the "optical width" concept to achieve the dominance of the vertical elements. The paper describes good examples of where traffic calming technices are used through Ireland. In 2002 the National Roads Authority published the Evaluation of traffic Calming Schemes constructed on National roads from 1993 to 1996 (2). This paper describes the results and the positive effects of Traffic Calming.