ENV 12313-1 : 1998

Contents
1. Application
    1.1 Definition of the TMC "travel service"
    1.2 TMC virtual terminal
    1.3 Event-oriented driver information messages
    1.4 Strategic and tactical information
    1.5 Geographic relevance (CEN TC278 SWG7.3)
    1.6 Transmitted message priority
    1.7 Event catalogue
    1.8 Future extensions
2. Presentation
    2.1 TMC virtual language
    2.2 Message content
         2.2.1 Event description (11 bits)
         2.2.2 Primary Location (16 bits)
         2.2.3 Direction and Extent (4 bits)
         2.2.4 Duration (3 bits)
         2.2.5 Diversion advice (1 bit)
    2.3 Implicit information
    2.4 Optional message content
         2.4.1 Control codes (label 1)
         2.4.2 Length of route affected (label 2)
         2.4.3 Speed limit (label 3)
         2.4.4 Additional quantifiers (label 4 and 5)
         2.4.5 Supplementary information (label 6)
         2.4.6 Start and stop times (label 7 and 8)
         2.4.7 Multi-event messages (label 9)
         2.4.8 Detailed diversion instructions (label 10)
         2.4.9 Destinations (label 11)
         2.4.10 Cross linkage to source of problem (label 13)
         2.4.11 Separator (label 14)
3. Message Management
    3.1 System messages
         3.1.1 Location database
         3.1.2 Receiver requirements
         3.1.3 Change of database numbers
    3.2 Message repetition
    3.3 Message updating
    3.4 Message deletion
         3.4.1 Message persistence
         3.4.2 Detailed stop-time
         3.4.3 Silent cancellation message
         3.4.4 Null message
    3.5 Message presentation
    3.6 Out of Area Referencing
         3.6.1 Structure of the EUROAD concept
         3.6.2 EUROAD messages
         3.6.3 Updating and cancellation of EUROAD
                messages
4. Transmission
    4.1 Format of type 8A groups
    4.2 Immediate repetition
    4.3 Single group user messages
    4.4 System messages
         4.4.1 System information
         4.4.2 Tuning information
    4.5 Multi-group messages
         4.5.1 First group
         4.5.2 Subsequent groups
    4.6 Addendum:Type 8A groups used by ALERT C and
         ALERT Plus

Alert C protocol covers event-orientated driver information messages. Provision has also been made for the subsequent definition of other applications, such as pan-European digital cellular radio (GSM) system, AM broadcast data systems, and digital audio broadcasting (DAB).