Purpose: To notify drivers in advance of special changing traffic conditions and roadway configuration changes associated with road construction or maintenance in order to reduce driver confusion that could result in a crash.
The Manual on Uniform Traffic Control Devices (MUTCD) contains the national standards governing all traffic control devices. DMS (described as Changeable Message Signs in the MUTCD) are one traffic control device covered by the MUTCD (MUTCD 2009 Edition Chapter 2L. Changeable Message Signs. In MUTCD Section 2L:
Section 2L.01 addresses the description of Changeable Message Signs;
Section 2L.02 addresses applications of Changeable Message Signs;
Section 2L.03 addresses legibility and visibility of Changeable Message Signs;
Section 2L.04 addresses design characteristics of Changeable Message Signs;
Section 2L.05 addresses message length and information of Changeable Message Signs:
Section 2L.06 addresses installation of permanent Changeable Message Signs.
The planning guidelines are intended to be an additional tool to assist agencies in the decision process of selecting when and where to deploy DMS technologies, based up the experiences of agencies that have previously deployed DMS.
Engineering judgment should be used to asses potential implications that may result from installation of DMS. This planning guidance does not mandate the use of DMS.
The guidelines do not distinguish between types of DMS (portable, overhead, roadside). Rather the intent of the guidelines are to contribute to the understanding of the need for some type of DMS. Detailed design would contribute to the selection of the specific DMS type.