The Traffic Message Channel (TMC)

TMC is a specific application of FM RDS used for broadcasting real-time traffic and weather information. Data messages are received silently and decoded by a TMC-equipped navigation system, and delivered to the driver, typically by offering dynamic route guidance – alerting the driver of a problem on the planned route and calculating an alternative route to avoid the incident.

How does it work?

The service provider sends the coded messages to the appropriate FM radio broadcaster for transmission as an RDS (Radio Data System) signal within normal FM radio transmissions. The TMC data are received by the vehicle radio and antenna, and decoded by a TMC decoder.

This reconstructs the original message, using a database of event and location codes, which is presented to the driver as a visual or spoken message. Standard TMC user messages provide five basic items of broadcast information: event description, location, direction and extent, expected duration, diversion advice.

Benefits for users

  • Updated traffic information, delivered in real time
  • Instant knowledge of accidents, roadworks and traffic jams
  • Filtered information only for the immediate route
  • Information in user’s own language
  • High-quality digital transmission
  • Standardised compatibility of receivers
  • Widespread service delivery across Europe, in the USA and in many other countries worldwide

TMC Services today

TMC is available in many countries around the globe. More information regarding the current status of deployment is available Here