Analysis and Evaluation of the German Toll System Using a Holistic Executable Specification

The European Electronic Toll Service (EETS) allows different possibilities for the overall system design of interoperable toll systems. We study the effect of the overall system design on the operational costs using a model based, holistic, executable specification. The model is set up to give an accurate description of the interdependences as seen in the German toll system. Two different scenarios are simulated and compared. The first scenario simulates the on-board toll calculation (as used in the German toll system), the second scenario corresponds to backend toll processing. The simulation gives an accurate figure for the operational costs associated with this design decision. A comparison of the cost of financing (of not yet processed toll fees) with the cost of communications is derived from the simulation results and allows choosing the right system architecture and system parameterization according to minimal operational costs.