Drivers in Germany can get real-time computer-generated advice about traffic jams on the country's autobahn system using cell phones or electronic consoles in their cars. The system, called Tegaron Telematics, is a joint venture of phone company Deutsche Telekom and DaimlerChrysler.

The system, launched two years ago, has about half a million console-equipped users and many more who tap in by phone. The partners plan to expand it and hope it will cover cities and towns all over the country.

Although no American system appears to have reached Tegaron's level of integration, some are catching up. San Antonio's four-year-old TransGuide scans traffic patterns with a variety of monitoring technologies that include a network of sensors and 45,000 electronically "tagged" vehicles. It shares the information with local radio and television broadcasters and posts information about tie-ups on electronic billboards and via the World Wide Web (www.transguide.dot.state.tx.us).

1. About 4,000 infrared sensors set up along 5,000 miles of the country's autobahn system count each car going by. Computers digest that data to calculate speed and density of traffic and figure out where jams are occurring.

2. Drivers can dial 2211 on a cell phone to get traffic information, for a charge of about 60 cents. Using signals from the phone, the system calculates the rough location of the car and serves up relevant traffic information. If conditions change, the system calls the driver back every 15 minutes for an hour.

3. Drivers of certain car models, including the Mercedes-Benz S-class, can buy special consoles for their cars that allow the system to monitor the car's location and send it traffic advisories as deemed necessary. The car's location is tracked through a Global Positioning System unit that sends out reports on cellular phone frequencies.

4. The GPS location reports from the console-equipped cars are fed into the traffic- jam database as they arrive. Tegaron hopes that as more cars get the consoles, second-by-second GPS data from millions of cars will replace the data generated by the less precise highway-side sensors.

5. If a console-equipped car is involved in an accident, a separate system automatically alerts emergency authorities, as select systems in the United States are already doing. Tegaron hopes that eventually electronics in the car will perform simple diagnostic tests and report the results to a roadside assistance company, so that service technicians will know what parts to bring out.

6. Privacy concerns? Deutsche Telekom notes that the system is voluntary. Anyone who doesn't want the company to know a car's every move can simply opt not to buy the GPS system.