Multi-day European heat waves with temperatures topping 104 degrees Fahrenheit (40 degrees Celsius) are increasingly leaving their mark on Germany's famed Autobahn — buckling concrete slabs, deforming asphalt and forcing temporary speed limits. So, as heat waves intensify and traffic volumes rise, are Germany's roads built to last? At present, road surfaces have to be designed for a temperature range of minus 30 degrees Celsius to plus 45 degrees Celsius, according to Autobahn GmbH. Just scattering light-colored quartzite over the asphalt surface could also help, according to Stelzenmüller, and would be a short-term, feasible approach. Tokyo, for example, already uses reflective, water-retaining road surfaces as standard when resurfacing streets.