The effectiveness and safety of traffic and non-traffic related messages presented on changeable message signs : technical summary.

632358197Technical summary.PDFTech ReportMN/RC-2008-27(c) 89261 (wo) 27Variable message signsSimulationMinnesotaMinnesota. Dept. of TransportationHarder, Kathleen A.Bloomfield, John R.University of Minnesota. Center for Human Factors Systems Research and DesignMinnesota. Dept. of Transportation. Office of Research ServicesNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic Control DevicesUS Transportation CollectionChangeable message signs are electronic devices used along roadways to provide drivers with guidance related to traffic conditions and other events. Displayed messages can suggest that drivers take alternate routes in response to congestion, accidents or roadwork zones. CMSs are also used to display time-critical information not related to traffic control, such as Amber alerts regarding child abductions, as well as messages not specific to a time or roadway condition, such as \ue2\u20ac\u153Don\ue2\u20ac\u2122t Drink and Drive.\ue2\u20ac?Evidence suggests that CMSs can disrupt traffic flow by causing drivers to slow down. Further, the content of messages displayed on CMSs may not be adequately comprehensible to allow drivers to respond to them appropriately. Finally, using CMSs to display both messages that are time-critical and those that are not may lead drivers to pay less attention to either type of message.Phase I of a study into these issues, conducted in 2003, measured the effect of the more complex CMS messages Mn/DOT was using at the time. Further study was needed to perform assessments of CMSs with newly developed wording that more clearly conveyed the intended message to drivers