Brief

Hesse’s state capital of Wiesbaden has commissioned Siemens Mobility to implement its “Digitalization of Traffic” (DIGI-V) project, which is based on the city’s Green City Plan – Masterplan WI-Connect. Wiesbaden is lowering traffic-related nitrogen oxide emissions with an extensive air pollution control package covering all areas of mobility. To achieve this reduction in traffic-related emissions, extensive environmental and traffic data will be recorded, analysed and processed in real time.

Big Data

The system requires a large volume of data and information provided by cameras and sensors that quantitatively and anonymously monitor the traffic volumes of a variety of users such as vehicles, bicycles and pedestrians. Additional information covering public events, the city’s mass transit systems and the changing parking situation is also included in the system’s analysis, along with data provided by environmental sensors.

With the help of Big Data analytics, the flow of data from the various sources above can be processed and linked. Correlations can then be determined from the analysed environmental and traffic data, and appropriate measures can be identified. These real-time analyses are the basis for active, environment-sensitive traffic controls.

Prediction and Decision Support Tool

Three different systems will work together to achieve traffic and environment-oriented simulation-based forecasting:

• Sitraffic Concert traffic management system by Siemens provides visualization of the simulation-based prediction; realization of traffic management strategies; visualization and user interface of the workflow for simulation and presentation of the corresponding results and indicators (KPIs)
• Aimsun Live: continuous traffic forecasting and response plan comparisons to help TMC operators choose the best strategy in the case of non-recurring events
• IMMIS: Emissions calculations based on Aimsun Live traffic predictions

The three products exchange data; the data required for simulation-based prediction are transmitted on a permanent cycle. This process takes place automatically without any user interaction.

User interface and workflow

In conjunction with Aimsun Live, Concert is able to simulate the impact of different traffic management scenarios that involve one or a combination of the following traffic management strategies:

• Traffic diversion using variable message signs
• Variable speed limits
• Signal plans of light signal systems

The traffic control room operator can manually activate the traffic management strategies available for simulation with immediate effect for up to 3 different scenarios.

After completion of the simulation, the system presents the operator with a comparison of the simulated scenarios with key performance indicators (KPIs) in order to communicate their effectiveness and usefulness in system optimization. KPIs communicate traffic and environmental situations.

In addition to the KPIs, the simulation produces a traffic score based on the traffic KPIs and a formula. The higher the rating, the more suitable the scenario is for implementation from a traffic management point of view. This formula and the KPIs to be considered must be defined in order to reflect Wiesbaden’s traffic management needs. In addition, the simulation provides an environmental assessment based on IMMIS. The higher the rating, the more environmentally friendly the scenario is for implementation.