This article describes a newly developed adaptive traffic light control system from German manufacturer Siemens AG. The three-level control conceptfeatures traffic management level, tactical (adaptive) level, and operational level. The system, Sitraffic MOTION, sends adapted signal plans to controllers every ten minutes, allowing changes in the structure and algorithms of the network control methods. Use of the system in the city of Copenhagen, Denmark, increased the speed of public transport without slowing private traffic. In the event of detector failure, an average value is generated which has been shown to be almost always correct. A new cycle-based queue-length estimation method allows back-up lengths further back from thestop line to be estimated and delays to be computed. It is possible to use algorithms that determine optimum co-ordination of patterns on similar traffic situations. The new system was installed in the city of Munster, Germany and improved traffic flows.
Abstract