The HEIDI project aimed to enable safe, efficient and widely accepted interactions between vehicles and vulnerable road users, including those with different automation levels and reduced physical or cognitive abilities due to age, distraction or temporary conditions. Responding to the European CCAM strategy and Vision Zero, HEIDI addressed the need for human-centred, inclusive communication between automated vehicles and people in complex traffic environments.
Adopting a holistic approach, HEIDI treated drivers and external road users as active components of one cooperative system. Its objectives were to develop and demonstrate fluid, cooperative human–machine interfaces (HMIs); create innovation modules for mutual awareness; establish validation methods for cooperative HMI solutions; and produce recommendations for regulation, standardisation and adaptive HMI design.
In the second half of the project, HEIDI advanced from concept to prototyping and real-world validation. Internal (iHMI) and external (eHMI) interfaces were implemented in two demonstration vehicles, while the cooperative HMI (cHMI) was validated in a co-simulation linking a driving simulator and virtual pedestrian lab. Studies with over 150 participants confirmed clear benefits: iHMI reduced reaction times and perceived danger under distraction; eHMI improved clarity and cut time-to-resolve by up to 1.9 seconds; cHMI enabled cooperative resolutions in 77% of interactions versus 46% in baseline conditions.
HEIDI also developed the Osmotic Layer, a software architecture ensuring real-time data exchange between internal and external systems, and produced guidelines for design, validation and ethics aligned with the European Common Evaluation Methodology for CCAM (EU-CEM). The project contributed to regulatory work within EuroNCAP, IEEE and UNECE WP.29 supporting future standards for external and cooperative HMIs.
Social sciences and humanities were integral throughout. Human factors, psychology and ethics guided user needs analysis, interface design and validation to ensure inclusivity across ages and abilities, overseen by an external ethics advisor.
By combining technical innovation with human-centred design, HEIDI offers a validated pathway toward foresight safety—anticipating and preventing hazards before they occur. The results strengthen Europe’s leadership in safe, ethical CCAM, with strong uptake potential and direct relevance for future vehicle regulation. Expected impacts include shorter interaction times, greater public acceptance of automated mobility and improved safety for all road users.
