Intelligent Transportation Systems

Data acquisition and processing

Input interface

Data from telematics devices and traffic information from external systems are passed to an input interface module in the agreed XML format from all communication modules.

The input interface module performs data validation, checks the XML structure and mandatory attributes. If validity is verified, the module will provide conversion and storage of data in the data warehouse.

Data processing and evaluation

The module processes and evaluates data that were received by the system via the input interface. The module provides calculations of aggregate traffic characteristics obtained from traffic detectors at certain points in time – a calculation of the average values of traffic characteristics over a certain time interval is performed. An example is the data from detectors which use aggregate values at five-minute intervals for monitoring the current traffic conditions. For archiving and use in traffic engineering, an hourly aggregation is usually expected. All values thus calculated are stored in the data warehouse.

Rules for processing the input data are defined in the database of data processing and evaluation guidelines.

Traffic situation calculation

The module provides traffic situation calculations on the basis of information obtained at given road sections. The traffic situation is represented by an Alert-C code or code group and indicates the current traffic situation at the given road section (traffic volume, passability, etc.)

The module can calculate, for example, the traffic volume using the data obtained from traffic detectors – the traffic volume is then classified on a scale of 1 – 5. The traffic volume can be calculated from the data from various telematics detection devices - detection loops, video detection, strategic detectors, traffic light detectors, etc. All calculated values are stored in the data warehouse.

For the calculation of the traffic situation, the module uses a set of rules which are controlled by an administrator.

The traffic situation is defined by

  • name and description
  • selection of Alert-C codes for traffic incidents

Calculation of travel time

The module makes calculations of information on travel on the defined road sections based on all available information – mainly from automatic traffic detectors. The module takes into account information on closures, traffic congestion, etc.
Information on travel time is calculated (updated) at five-minute intervals.

Prediction of traffic situation

The module makes calculations of the predicted traffic situation on the basis of information on the current traffic situation and on the historical development of the traffic situation. Based on this information, the module performs a calculation of the predicted state at every change in the traffic situation. If necessary, the warning module sends a warning message to the operator about the predicted traffic situation.