California Partners for Advanced Transportation Technology

This document presents a review of the Traffic Management Data Dictionary (TMDD) standard, specifically version 3.03d with some analysis of the newest version 3.1, released in January 2020. The intention of this document is to provide a review of this standard for transmission of data between traffic management centers (TMCs), with specific commentary on usability of the standard with specific examples based on its implementation in the Caltrans I-210 Connected Corridors program. TMDD is published by the Institute of Transportation Engineers (ITE), an international organization of transportation engineers and the American Association of State Highway and Transportation Officials (AASHTO), an organization of highway and transportation officials in the United States with members from all 50 states, the District of Columbia, and Puerto Rico. The standard is provided in two parts, along with a reference guide, providing guidance for those developing, procuring, or implementing systems that communicate traffic and transportation device information between or within traffic management centers (TMCs). This includes information regarding system requirements, interface design, communication methods, as well as data schema and definitions.