The term "silent policeman" refers to a traffic cone or barrier used to mark obstructions on the road or act as a guide. There are various synonyms for this term, including speed bump, hump, sleeping policeman, traffic cushion, and road bump. Some other regional variations include judder bars, speed breakers, and speed tables. These terms are used interchangeably to refer to devices or structures that help in reducing the speed of vehicles and minimizing accidents. The use of such devices is essential in ensuring the safety of pedestrians and motorists, and a proper understanding of the different synonymous terms is crucial for effective communication and enforcement of traffic regulations and standards.