Abstract
To collect, manage and distribute traffic information, the Swedish National Road Administration (SNRA) uses a common national system, TRISS (TRaffic Information Support System). The TRISS system is today in use at all traffic information centres in Sweden. All information is replicated between the centres and whenever needed, one centre can act as a stand-in for any other centre. In addition to SNRA's internal information (roadworks, road conditions, frost damages etc...), the TRISS system also deals with information from other sources such as SOS Alarm, Swedish National Radio and the police force. Based on the information entered in TRISS, RDS-TMC messages are automatically generated and transmitted on the RDS channel.