WETSAFE

The WETSAFE project developed an effective and robust methodology for the early detection and assessment of safety-critical hazard spots on motorways resulting from heavy rainfall events. The aim was to support road safety and the availability of high-priority road infrastructure, even in the face of increasing climate-related extreme events. The focus was particularly on local risks such as aquaplaning, water accumulation and unexpected flow paths, which are often not immediately apparent to road users or vehicle systems.

At the heart of the project is the combination of a high-resolution digital twin of the motorway and its surrounding area with hydrological and hydraulic simulations. This has made it possible, for the first time, to realistically account not only for the effects of rainfall on the carriageway itself, but also for inflows and outflows from the adjacent terrain. The simulations showed that critical hazard points arise primarily from the interplay of several factors and are often highly localised. Using the methodology developed, these hazards can be identified down to the level of individual lanes or road sections; within the project, they were consolidated into reliable, section-specific risk zones, which form a robust basis for warning and decision-making processes.

Based on the simulation results, the study also examined how warnings about specific road conditions can be integrated into existing information and communication systems (C-ITS). It emerged that warnings about water on the carriageway or unexpected water flow paths are particularly effective, whilst general heavy rain warnings offer only limited added value. The project results demonstrate that suitable message types and parameters are already available in principle within existing standards and can be utilised for operational implementation.