Abstract
Effective traffic management systems depend on the use of intelligent techniques for data collection. The authority of Dsseldorf tested two different systems to gain extensive information: video detection and infrared sensors. Afterwards the first 41 detection stations were built on the main roads. The traffic data is transmitted to the control center by the existing twisted-pair cable communication infrastructure or by GSM radio. All subsystems (e.g. alternative route guidance systems, web-server, traffic signal control system) have access to the data bank in the control center for their special applications. The total traffic management system is scheduled for completion by the end of 2007 with overall costs of about 25 million.