Green wave in Muenster: Adaptive signal control from Siemens offers car drivers a 30 percent improvement in flow of traffic

Representative of these solutions will be the “green wave for Muenster”, where road users benefit from a succession of green lights more frequently thanks to the Sitraffic Motion adaptive network control system.

Since the middle of last year, the new procedure analyzes the current traffic situation on a main artery and then automatically optimizes the red-green phases of the traffic signals at the 24 intersections on this road. The result is an average 30 percent reduction of driver waiting times at traffic lights.

This figure was corroborated by a study done by Ruhr-Universität Bochum and published at the beginning of 2009. Fuel consumption and exhaust emissions are reduced as well. These results certainly convinced the people of Muenster, and the city council has decided to link up a second main traffic artery to the Sitraffic Motion system in the near future.

Starting in 2006, Siemens installed the Sitraffic Motion traffic control system at 24 traffic signal-controlled intersections on the heavily traveled Albersloher Weg in Muenster. This was done in connection with a new traffic computer system. By means of detectors mounted in the approach roads, Sitraffic Motion determines how many vehicles are underway, where they turn off and where there is an imminent threat of congestion.

A central traffic computer receives the data, analyzes the traffic situation at the intersections along the six-kilometer-long road in 15 to 20 minute cycles and automatically adapts the lengths of the red-green phases of the traffic signals as well as the green wave accordingly. In June 2008, installation on the road used as a model was completed. The result: traffic flows more smoothly, there are fewer stops, and waiting times for car drivers are shorter. Fuel consumption and exhaust emissions are also reduced as a consequence.

The success of the new method has been confirmed by a representative study carried out by Ruhr-Universität Bochum. The study compared the three development stages of the traffic system in use on Albersloher Weg: the original situation with fixed time control, the conventionally planned, traffic-dependent control unit in the individual traffic signal installations and, finally, the Siemens approach in the form of the traffic-adaptive control system, also referred to as a model-based system. The team surrounding Prof. Werner Brilon at the university’s Institute for Transportation and Traffic Engineering used values from their own measurements with detectors, GPS (Global Positioning System) and video vehicles as well as the telematics data of the city’s public transit system.

“The level of improvement has been unexpectedly high,” summarized the authors of the study, who went on to say that the adaptive control system brought about a further improvement in traffic quality compared to a traffic-dependent control method.

In view of the excellent success achieved in Albersloher Weg, the Muenster city council decided to equip another busy road with the new control system from Siemens in a subsequent construction phase.

You can download the study at the following link (available in German only):

http://www.muenster.de/stadt/stadtplanung/pdf/albersloher-weg_lsa_bericht2009-01.pdf

The Siemens Industry Sector (Erlangen, Germany) is the worldwide leading supplier of production, transportation, building and lighting technologies. With integrated automation technologies as well as comprehensive industry-specific solutions, Siemens increases the productivity, efficiency and flexibility of its customers in the fields of industry and infrastructure. The Industry Sector consists of six Divisions: Building Technologies, Drive Technologies, Industry Automation, Industry Solutions, Mobility and Osram. With around 222,000 employees worldwide, Siemens Industry posted a profit of EUR 3.86 billion with revenues totaling EUR 38 billion in fiscal year 2008 (ended September 30).

The Mobility Division (Erlangen, Germany) is the internationally leading provider of transportation and logistics solutions. With its “Complete mobility” approach, the Division is focused on networking the various modes of transportation in order to ensure the efficient transport of people and goods. “Complete mobility” combines the company's competence in operations control systems for railways and traffic control systems for roadways together with solutions for airport logistics, postal automation, traction power supplies and rolling stock for mass transit, regional and mainline services, turnkey systems as well as forward-looking service concepts.

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