Portable Speed Limit Signs and Radar Speed Trailers
Typical portable radar speed trailer.
Portable speed limit signs are movable signs that remind drivers of the posted speed limit. Radar speed trailers alert each passing driver to their traveling speed. These machines are used in some jurisdictions along with law enforcement. For example, the signs are put in place, parents are notified that law enforcement will be present, and then officers show up to ticket speeders and drivers who fail to stop for children in marked crosswalks. In other locations, signs are used with no further enforcement activity. Portable speed limit signs are discussed further in Enforcement.
For more information on traffic calming in school zones visit the 2004 PEDSAFE Guide "Radar Trailers in Neighborhoods" Bellevue, Washington, case study.