Austroads (2004) promotes speed based design when installing LATM s and states that there is very little systematic information available on device crossing speeds; there is even less reliable information on whether or not operating speeds can be given for a given type of device . This book has been prepared for practitioners,and is based on research that investigates the effectiveness of traffic calming devices installed on local roads at twenty one locations in New Zealand. It compares the installation criteria and the resultant effects with the findings sourced from a literature review, and makes recommendations for further research.