Nowadays, many cities in the world are suffering from problems like congestion, pollution, and traffic accidents which are caused by vehicular traffic. The correct scheduling of traffic lights can help to alleviate these problems by improving the flow of vehicles through the cities. The main aim of this dissertation is to build an approach to find the good traffic signal plans for a large area. The two major features of the approach developed in this thesis are real-time and system-wide. Since traffic flow changes with the time of day, the real-time computation of the traffic signal plans can improve the operation efficiency of traffic lights compared with fixed signal plans which is an old but still often used technology in the world. The proposed approach is the serial optimization with a hierarchical control framework. The upper level is the level for macro control strategies including a network partition strategy and a network signal coordination strategy. The network partition strategy means that the urban network is partitioned into smaller sub networks based on the network's topological graph and intersections' priority order. The priority order is computed by the sorting model of priority order (SMoPO), which offers the opportunity for the higher priority intersection to be coordinated earlier and to obtain more benefit. The network signal coordination strategy is developed to determine which intersections form a coordination pair and which traffic streams need to be coordinated. This strategy converts the optimization problem into a much simpler one. The number of operations and the computation time to solve this optimization problem drops largely. The lower level is the level for micro parameters calculation, in which a method for the computation of the optimal relative offsets is proposed which is based on cyclic flow profiles. All of the developed strategies were programed and interfaced with the microscopic simulation tool "SUMO". To verify the success and the dynamic feasibility of strategies, the computation speed tests were done in three-by-three to sixty-by-sixty grid nets to demonstrate the real-time feasibility of the approach. After that, microsimulation studies have been performed to evaluate the performance of the strategies. The first case study was a hypothetic eight-by-eight grid net with varied traffic demands and link lengths, and the results revealed that the strategy was effective when the intersections were not oversaturated. The others were two real networks in Braunschweig City, whose input data was from the Project AIM (Application platform Intelligent Mobility). The simulation results showed the delay time was decreased on average in both cases compared to Webster's model.


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    Titel :

    Dynamic Network-Wide Traffic Signal Optimization


    Weitere Titelangaben:

    Dynamisch-netzwerkweite Lichtsignalanlagenoptimierung


    Beteiligte:
    Lu, Ting (Autor:in) / Universitätsbibliothek Braunschweig (Gastgebende Institution) / Kücükay, Ferit (Akademische:r Betreuer:in)

    Erscheinungsdatum :

    2015



    Medientyp :

    Sonstige


    Format :

    Elektronische Ressource


    Sprache :

    Englisch


    Klassifikation :

    DDC:    629