Vehicle-to-X communication, i.e., the exchange of sensor information between vehicles and road infrastructure such as signs and traffic lights, increases traffic safety. However, the data is heterogeneous and varies in terms of its significance: it comes from different sensors, such as laser scanners (lidar), radar, or cameras, from different manufacturers, and varies in reliability depending on the situation—for example, in heavy rain. In the ConnRAD project (“Connectivity & Resilience for automatic driving functions in Deutschland”), the Smart Mobility team at Fraunhofer FOKUS has worked with partners from industry and research to develop ways of designing, developing, and approving networked traffic systems.

The Fraunhofer FOKUS research team has expanded the vehicle-to-X communication protocols to include the transmission of information on sensor quality, i.e., information about the type and capabilities of the information source. This extension has been integrated into the software of the automated research vehicles, enabling them to make autonomous decisions based on the enriched information and a hierarchy of sensor quality. For example, lidar information is considered more reliable than radar data, as lidar sensors can also detect slow-moving vehicles well.

With the help of the use case “Turning left at an urban intersection,” Fraunhofer FOKUS and Bosch, the consortium leader of the project, demonstrated that this additional metadata increases safety at intersections. At the final event at October 23, 2025, on the Bosch test track in Renningen, the team presented this in a demo with three variants:

• Infrastructure-to-vehicle communication, intersection clearance without metadata. Result: A collision would occur if the driver did not intervene.
• Infrastructure-to-vehicle communication, intersection clearance with radar source information. Result: The vehicle recognises that there is no high reliability and would abort the left turn.
• Infrastructure-to-vehicle communication, intersection clearance with radar and lidar source information. Result: The vehicle can turn safely.

Bernd Schäufele, scientist at Fraunhofer FOKUS, explains: “In the ConnRAD project, we have taken automated, connected vehicle-to-X communication to the next level with our partners from industry and research. Information on the quality of the information source is not yet included in the standard for collective perception of the European standardization organization ETSI. We will now work towards its integration to increase the safety and resilience of connected driving.”

The project consortium included Bosch (consortium leader), Daimler Center for Automotive IT Solutions (DCAITI), Fraunhofer FOKUS, Fraunhofer IEM, Saarland University of Applied Sciences (HTW Saar), Infineon, Technical University of Munich, TÜV Süd, and the University of Ulm.

The German Federal Ministry of Research, Technology, and Space funded the three-year project as part of the guideline for promoting research projects on “Resilience – Resilient Digital Systems” within the research program for communication systems “Sovereign. Digital. Networked.”

ConnRAD project website

Bosch press release (in German)