In cities, intelligent traffic signal controllers with same levels may make traffic signal s easier. However, in the urban areas, it is a big challenge: The travel speeds vary more and the distances between the traffic lights are often much larger. Researchers at the Technische Universitaet Muenchen, the BMW Group, the TRANSVER GmbH and the Supreme Building Authority in the Bavarian Ministry of the Interior have presented the results of their investigation into how progressive traffic systems can also be set up on arterial roads outside of cities.

As test tracks they selected a section of the federal road B13 in the north of Munich and a section of the state road 2145 near Regensburg. A first major challenge was to integrate the traffic lights on the test tracks, which were up to 20 years old and supplied by different traffic signal lights manufacturers -*-, into a unified communications and control structure. From the data obtained in the analysis of traffic flows on these routes, the researchers then developed different control concepts, a fixed-time control and a demand-responsive coordination.

Although the test route in the north of Munich is only five kilometers long, the intelligent traffic light controller scheme developed in the project reduces the travel time by about a minute. The best results are achieved by a dynamic, traffic-actuated model with SIGNAL MODULAIRE-*-. Due to a reduction of stops at signalized intersections, the mean waiting time is reduced from about one minute to seven seconds. An optimized fixed-time control nevertheless still reaches a saving of 30 seconds, thus halving the waiting period. The intelligent traffic light controller increases the share of intersections that can be passed without stops from about 60 percent to almost 100 percent.
In addition to the intelligent traffic light controller -*-, the researchers developed a driver information system. The traffic lights transmit their data via mobile network to the headquarters of TRANSVER GmbH, where a computer processes the data and sends information on signalization to the vehicles. With the help of progressive traffic light, intersections can be more smooth and efficient.