Permeable pavements, unlike conventional asphalt paving, allows water to pass through the surface, reducing storm water runoff and pollution in waterways. Research by the University of Melbourne aims to make permeable pavements more resilient to heavy loads. The flexibility provided by the combination of soft tyres and rigid crushed rock particles, bonded together by a polyurethane binder, can be used to reduce cracks caused by movements by natural ground while sustaining light traffic loads. The high infiltration rate of this blend can be used to reduce the impacts of flash-flooding.