Kai-Uwe Thiessenhusen

New Approaches for Traffic Management in Metropolitan Areas

Abstract The paper outlines concepts and results for innovative approaches in urban traffic management. The increasing availability of traffic sensor data from stationary as well as floating car data sensors have been improved the methodology for traffic monitoring, traffic forecast and traffic management strategies. In the paper the technical features of a real-time FCD system operated in various German and European cities like Berlin, Stuttgan, Vienna etc. are described. Furthermore, the developed data processing algorithms for the reconstruction link-based and spatial traffic data are underlined. Finally, a traffic control strategy for urban areas will be discussed.

Specifica of Fundamental Diagram in Urban Traffic

The relation between the fundamental quantities flow, density, and speed is well studied empirically in “undistorted” traffic, i.e. traffic on highways or major non-urban roads. The situation on urban roads is more complicated since urban traffic is influenced by a number of effects. Especially, the situation at intersections (traffic lights, merging traffic) is of striking importance.

Approximating Traffic Flow by a Schrödinger Equation - Introduction of Non-Reflecting Boundary Conditions

We show that some simple urban traffic flow equations can be approximated by equations which are equivalent to a Schrodinger equation. For a simulation of the Schrodinger equation as well as for analytical computations it is useful that waves of traffic which travel along a road are not reflected at the boundaries of the simulated region. We present the non-reflecting boundary condition for a corresponding one-dimensional Schrodinger equation, and show simulation results for a wave package of traffic moving towards such a boundary.

Simulation tool for space borne traffic data collection

Space borne traffic data collection is an important method to complement surface and air borne data. We present a first version of a simulation tool that analyses the feasibility of detection of traffic situation over large areas using radar sensors on satellites and airplanes. With this tool it will be possible to evaluate the information content of traffic data acquired by any given sensor. In this tool, the processes determining traffic data collection with space borne radar sensors are reconstructed. All relevant features for traffic monitoring, starting with the traffic scene followed by the sensor and traffic data extraction and interpretation, are simulated. The simulation tool has a modular structure. Each module is independent and exchangeable and describes one separate part of the traffic remote sensing process. The modular structure of the software guarantees maximum flexibility and portability. Changes in one module do not necessarily require changes in other modules. This tool is suitable for a precise specification and optimization of sensor and satellite parameters for traffic data collection. The results can be applied to future satellite missions.