The Institute of Transport, Railway Construction and Operation (IVE) at the University of Hannover, Germany, has developed a strategic network planning and traffic evaluation model (NEMO: Network Evaluation MOdel). This simulation tool enables infrastructure managers to evaluate the effects of changes to the existing network. Furthermore, it is an instrument to estimate the efficiency of new transport services. The model consists of several modules for projecting infrastructure, passenger traffic, and freight traffic. On the basis of train numbers determined by these modules, bottlenecks are identified and eliminated by help of a module for the network evaluation. The module evaluating economic efficiency calculates the costs and revenues that are to be expected when realising the simulated scenario. The either given or planned railway network is projected by the means of an infrastructure graph that consists of nodes and links. Infrastructure attributes, influencing the services provided, expenses and revenues are assigned to the graph's components. The module for projecting the passenger traffic provides a comparison of the services offered and the capacity demanded. The basis for the simulation includes the restrictions imposed by the infrastructure and the current or planned passenger services. In an equilibrium process, offer is brought into line with demand. This is done by the help of a modal-split model, which determines the relation between railway and road traffic. The module for projecting the freight traffic is based upon traffic volumes between different regions, the infrastructure and the operational strategies (production systems) of rail freight traffic. The freight volumes by region are assigned to the freight access points within a region. In order to connect the freight access points, an origin-destination-matrix is created. The whole amount of freight is then assigned to the respective production systems of the freight traffic. In cases where the quantity between two freight access points exceeds a certain amount, direct block trains are created. The remaining transport volume is transported by the single wagonload traffic. These wagons are rearranged in marshalling yards. The module for the evaluation of the network is based upon the results of the two modules projecting passenger and freight traffic. The calculated train numbers are combined to the total infrastructure load. Since capacity-caused bottlenecks only occur during certain times of day, the network load is examined for separate time slices. Within the time slices, bottlenecks are identified and dissolved by the use of suitable modifications to the operation program. Subsequently, the module for the evaluation of economic efficiency calculates the arising costs and revenues on the basis of the computed transport supply and demand. For the covering abstract see ITRD E124693.
Samenvatting