Sitraffic Scala – Traffic Computer System

With the Sitraffic traffic computer system, Siemens has developed a solution that can smoothly perform traffic platform tasks. This includes for example, traffic condition surveillance, central traffic control, processing and storage of traffic data.

Traffic control with TASS

TASS (Traffic-Actuated Signalplan Selection) is a situation-based signal program selection.

Measured control

For optimum traffic control, recurring traffic situations, such as "heavy inbound traffic" or "stadium-bound traffic", and then allocated optimum signal plans.

Strategic detections provides the automatic identification of traffic situations. Threshold values are used for rule-based identification of the situations, and the relevant signal plans are then activated. Environment-based control is also possible by including data from the environmental detection in the algorithms.

Network control Sitraffic Motion

Sitraffic Motion stands for “Method for Optimization of Traffic In Online Networks”.

This software optimizes the traffic light system processes to ensure that the traffic flow improves measurably while the infrastructure remains the same.

Traffic focus

First of all, the Sitraffic Motion MX software module precisely assesses both the current and future traffic conditions based on measured data, and computes the optimum signal programs for the connected traffic light systems, with the help of innovative algorithms.

Network-related tasks are performed at the central control level.

These include:

  • Green time allocation

  • Green time period

  • Green wave between the intersections

The results are transmitted as framework plans to the individual traffic light systems.  These control the phase sequence second by second and, in this process, adjust the phase duration to accommodate any short-time fluctuations in traffic volume.  In addition, buses and trams are prioritized in the controllers.

Control which works

This control system is much more effective than conventional systems – thanks to the optimization of traffic at both local and central levels:

  • Timely response to the real traffic situation in the individual phase

  • Traffic jams dissolved in a targeted fashion

  • Ability to cope quickly with fluctuating traffic volumes

Our special focus is the dynamic adjustment of the green waves. Particularly during peak traffic in the morning and evening, it is possible to significantly reduce fuel consumption and emissions.

Route Control for Emergency Vehicles in the City

Emergency vehicles using only flashing blue lights and sirens pose a safety risk – both for the emergency vehicle itself and for traffic in general. Furthermore, there may be critical delays in emergency situations.

Priority light signal

In this area too, we offer an appropriate solution: In the case of an emergency, the operations control center demands a special traffic light program for the emergency route, which gives priority to the emergency vehicles by switching the signals to green. In this process, the route control can be adjusted in accordance with the position of the emergency vehicles.

Quality Management and Statistics

For center operators, the quality management and statistics of the various processes play an important role in traffic control.  Our modules provide support in this area:

  • Operational and Status Messages
    … are continually received and processed from all connected sensors and actuators. In the case of a failure or fault the system provides well-structured procedures for initiating fault clearance as quickly as possible.

  • Sitraffic Quality Management
    … monitors switching states such as waiting times at traffic lights for both pedestrians and vehicles, and travel times of public transportation vehicles. If/when threshold values are exceeded, this indicates a reduction in the quality of a traffic light system.  In such cases, this results in targeted improvement measures being initiated.

  • Online Visualization
    … is used to demonstrate the current and historical signaling states of individual traffic light systems. This also includes an online representation of green waves. In this way it is possible, for example, to retroactively determine the signaling state at any specific time, as may be required in the case of a court inquiry.

  • Sitraffic Statistics
    … performs extensive statistical evaluations of the data of all connected sensor types. These evaluations comprise various types of lists and graphics, such as the analysis of peak hours, representation of fundamental diagrams, daily traffic load curves at one-minute intervals or the yearly traffic load curves of daily traffic volumes.