01. February 2021

RISC Software: What Happened Last Night on the Motorway and Why?


Overhead signs on Austria’s motorways are important for maintaining the flow of traffic. Decisions regarding recommended speeds or warnings to be displayed are chiefly made by automated systems on the basis of data received from various sensors. For instance, at times of increased traffic volumes, as measured by vehicle counts, a speed limit is displayed on the relevant stretches. In the event of rain or icy conditions – detected by sensors – a warning symbol is displayed. In the event of a tailback, notification of where following vehicles will meet it is given several metres in advance on the overhead sign. Provision is of course also made for manual operation or override at any time.

Display decisions on overhead signs

In September 2020 the TRAPH project was launched with the aim of documenting these display decisions so that the sequence can later be examined and the reasons for it reconstructed. The project aims to enable analysis of messages displayed on overhead signs and the reasons behind them. To this end the relationships between the sensor data gathered along the stretch of road that led to the display decision taken by the overhead sign will be stored in a database. Apart from recording this data and making it available to the emergency services, for instance, the project’s other objective is to ascertain which messages are displayed most often along which stretches and which situations and measures result in specific displays. Another area of application is evaluation of message distribution over a given area. Analysis of this enables identification of accident black spots, for example, which can then be made safer.


Because the focus is on the causal links and reconstruction of the reasons for the displays, the project aims to compile a graph database to represent them. This type of database is particularly suitable for storing links of this kind because it can represent and store this closely linked data using nodes, edges and connections.

In the final expansion phase it should be possible to reproduce the display decisions taken all over Austria over a period of several years. RISC Software GmbH receives the data relating to the sensors, the measures and the switching decisions via a defined data streaming interface within the ASFiNAG network. The principal research task includes designing the data model for the graph database, an efficient method of gathering data from various data sources and storing it in the graph database.

Along with presenting the existing causal links, time-dependent relationships pose a particular challenge for data modelling because situations that depend on the weather, such as rain or black ice, can last longer and may still be affecting road conditions when the data is retrieved. Furthermore, data retrieval must be subject to flexible time limits to enable ASFiNAG to use the system effectively.

Project partners

Thanks to its data engineering expertise and the experience of NoSQL databases gained from the FFG traffic infrastructure research call in 2019, RISC Software GmbH was chosen to carry out the project and was tasked with selecting and designing the database solution as well as implementing the data transfer.

The Austrian highway operator Autobahnen- und Schnellstraßen-Finanzierungs-Aktiengesellschaft (ASFiNAG) is owned by the Austrian government and is responsible for funding, planning, constructing and maintaining federal highways and for collecting tolls based on journey duration and distance travelled.

Project details:

Name: TRAPH - High Performance Traffic Management Information System

Duration: 09/2020-02/2021 (6 months)

Funding scheme: Mobilität der Zukunft (“mobility for the future”), (FFG)

Project partners: Autobahnen- und Schnellstraßen-Finanzierungs-Aktiengesellschaft (ASFiNAG), RISC Software GmbH