Climate stress

Where does the road of the future lead?

Dr. Marius Mohr vom Fraunhofer IGB
© Heinz Heiss
Dr. Marius Mohr, Head of Innovation Field Water Technologies and Resource Recovery at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB.

“Road of the future” project

Optimizing the hydrological cycle is also an area of focus in the “Road of the future” project currently underway at Fraunhofer IGB and the Fraunhofer Institute for Industrial Engineering IAO. In one of two associated living laboratories in Ludwigsburg, Mohr and his team have built and commissioned a cistern below the road — the rainwater that drips from roofs and cars collects in this cistern

Storing water in the streets

Michael Würth, Projektleiter für Klimasimulation am Fraunhofer IBP
© Heinz Heiss
Michael Würth, Project Manager for Climate Simulation at Fraunhofer IBP

Building Physics of Urban Areas project

Another starting point for counteracting heavy rainfall and droughts lies in the road surface. Instead of sealing roads, cycle paths and sidewalks with asphalt or paving stones, teams of experts involved in the project “Building physics of urban areas” at the Fraunhofer Institute for Building Physics IBP are experimenting with a hydroactive road surface design. “Our newly developed system not only allows the water to seep out, it stores it mainly in underground stormwater detention layer — cavities in the ground that are enclosed by a watertight material,” explains Michael Wuerth, Project Manager for climate simulation. When it rains, these buffers fill up and counteract flooding, rather like any dry spell that might follow. For over the course of the next few weeks, wicking elements integrated into the underground stormwater detention layer transport the stored water back to the surface and emit it into the environment by means of evaporation. This also develops a cooling effect. Unlike commercially available underground stormwater detention boxes, which are interconnected as cubic underground reservoirs with a storage capacity of several thousand liters and therefore require a large ditch, the innovative, flat system can be integrated into the road without any notable additional work. “We are simply replacing one or more of the substructure layers required with our planar blind drain system,” explains Wuerth. The researchers are planning on the systems being able to take up to 200 liters of water per square meter. They are currently in the experimental phase.