This study has two main objectives; to evaluate the effect on safety of traffic calming of arterials and to look at the acceptance of traffic-calming measures. We found that there are only a few truly traffic-calmed arterials worldwide, and even fewer ones that have been evaluated. In North America, most traffic calming of arterials has occurred as a byproduct of mobility improvements, such as reducing roads from four lanes to three lanes with center turn lanes and constructing roundabouts. Stevens Avenue in Portland is an exception to that. The overall effectiveness of that project and other arterial traffic-calming schemes has been moderate even if there is a clear reduction in pedestrian injuries. The study of the general public's and city officials' acceptance of traffic-calming devices showed that humps and other vertical devices are less accepted than narrowed roadways and horizontal realignments. Given the public resistance to traffic calming of major arteries, the conclusion is that speed control through other means may, in the long run, be preferable to construction of humps and chokers on arterials. The public is in general in favor of having 'other people' comply with laws and regulations, including speed limits, but most people do not themselves voluntarily act according to such principles when is comes to speeding. Enforcement and public campaigns have some possibilities of achieving speed compliance but the authors' findings suggest that electronic, in-vehicle speed governors assuring legal speeds may be the most effective way of achieving speed compliance. This would probably result in fewer negative side effects than reconstruction of roadways.