Traffic Management Data Dictionary (TMDD) Standard for the Center-to-Center Communications

The Traffic Management Data Dictionary (TMDD) Standards were developed to support center-to-center communications as part of the regional deployment of ITS in order for centers to cooperate in the management of a corridor, arterial, incident mitigation, event management, etc. Hence the TMDD provides the dialogs, message sets, data frames, and data elements to manage the shared use of these devices and the regional sharing of data and incident management responsibility. As a result, the TMDD standards often reference elements of the NTCIP standards, but deal with the devices at a higher level of abstraction.

Version 3.1 represents an upgrade from Version 3.03d by changing how backwards and forwards compatibility is addressed by the standard, and separates how TMDD-specific extensions and project-specific extensions are handled. The focus on the TMDD (Traffic Management Data Dictionary) standard is exchanges that support shared use of ITS devices (e.g. Dynamic Message Signs, Traffic Controllers), sharing of roadway network status (e.g. traffic conditions), and shared management and monitoring of various types of traffic incidents/events. The standard is available in 2 volumes: Volume 1 contains the high-level Concept-of-Operations and Functional Requirements, while Volume 2 Design Concepts for  exchanging  information between traffic management centers (TMC)  and other external centers (EC) and also contains the Dialogs and Message content in XML format. In addition to the printed documents, the design content is also available in zip files in XML and WSDL and as XMLSpy output in HTML format.  The TMDD guide is now updated based on TMDD v3.1 standard and is available at this site.

Current Standard

Version No.

Standard Name

Overall Status Under Development / Published / Superseded Version

Date Approved


Traffic Management Data Dictionary (TMDD) Standard v3.1 for the Center to Center Communications


January 13, 2020
3.1 TMDD Guide v3.1 Published February 2020

Version History Table