Morocco is testing a ‘sponge’ pavement that drains water and cools itself through evaporation. For decades, black asphalt has rolled on the roads but parts of Marrakech and Agadir are reportedly becoming testing grounds for this new surface that is deemed to be environmentally better.The idea will not only make roads feel less hot during summers, but can also reduce runoff, improve drainage, filter some pollutants and cool itself through evaporation when enough moisture is available. Moroccan media describe limited experiments that replace selected areas of conventional bitumen with permeable pavement, allowing water to pass below the surface instead of sending every drop toward a drain, according to a report by econews.
Why not black asphalt?
During an Arizona pilot cited by the U.S. Environmental Protection Agency, conventional pavement reached about 152°F around midday, while specially designed cool surfaces remained 10°F to 16°F cooler.
Dark pavement absorbs solar energy during the day and releases part of it later as heat. This creates the “urban heat island,” the familiar pattern in which built-up neighbourhoods remain hotter than surrounding areas, sometimes well after sunset. The numbers are striking and worrying. During an Arizona pilot cited by the U.S. Environmental Protection Agency, conventional pavement reached about 152°F around midday, while specially designed cool surfaces remained 10°F to 16°F cooler. Anyone who has crossed a parking lot in thin-soled shoes knows the feeling.
The sponge alternative
Traditional asphalt forms a mostly sealed layer, so rainwater runs across it and into the gutters or sewers. But permeable pavement contains connected spaces that let water enter a stone base and where soil conditions permit, continue into the ground. Once moisture is stored below or within the surface, some of it can evaporate. Evaporation uses heat, much as sweat cools the human body, so the process may lower pavement temperatures while slowing the sudden rush of water during heavy rain.But there’s a catch. Research summarised by Rutgers University found that permeable concrete released 25% to 30% less heat than conventional concrete on days after rainfall, yet it could release slightly more heat on dry, sunny days. The cooling benefit depends on moisture, design, and local conditions.
The Moroccan experiment
Less heat radiating from roads and parking areas can make a walk, a bus stop or an evening meal outdoors more comfortable during the summer heat everyone fears.
The available reports describe experiments involving some urban surfaces and not a nationwide removal of black asphalt. The reported tests fit a broader shift in Marrakech. Its “Marrakech Sustainable City” program, launched in 2023, brings together Morocco’s Ministry of Energy Transition and Sustainable Development, local authorities, the United Nations Development Programme, and the Global Environment Facility to improve climate resilience, mobility, waste management, biodiversity, and energy efficiency.The program has $9.5 million in Global Environment Facility funding and is expected to benefit more than 1 million people directly. The pavement experiments are one possible tool within that wider agenda, showing how ordinary infrastructure can become part of climate adaptation.The experiment will have the clearest benefit for the drivers when the rain falls. Water that drains through a properly designed surface is less likely to remain in thick films, while the EPA says permeable roadways can reduce spray and improve traction through better drainage.A cooler urban microclimate could also lower the demand placed on vehicle air conditioning. That matters for gasoline cars and electric vehicles, but the Moroccan reports contain no measured EV range results, and any gain would probably be modest and dependent on weather, traffic, speed, and time spent on treated streets.The biggest payoff may be for the urban neighbourhood life. Less heat radiating from roads and parking areas can make a walk, a bus stop or an evening meal outdoors more comfortable during the summer heat everyone fears.However, permeable pavement can not be a replacement for every highway or busy avenue. Fine dirt, tyre debris, and sediment can clog its pores, so periodic cleaning and careful stormwater design are essential if the surface is to keep draining over time. Heavy traffic, extreme loads, and polluted runoff can also make certain sites unsuitable. That is why many current applications focus on sidewalks, plazas, parking areas, rest areas, and lightly travelled streets rather than promising a total end to conventional asphalt.Particularly, in Marrakech, rising temperatures and intensifying heat are already stressing the city’s infrastructure with water scarcity. When stored moisture disappears, evaporative cooling fades too, so planners must balance the desire for cooler streets with the need to use water carefully.
A step in the right direction
Across the Mediterranean, Spain tested a related idea through the “LIFE HEATLAND” project. Instead of relying mainly on water infiltration, its light-coloured pavement was designed to reflect more solar energy than conventional asphalt and store less heat. Murcia officials installed the material across roughly 258,000 square feet of city streets. At the time, the installation was designed to reduce road-surface temperatures by about 18°F and nearby air temperatures by roughly 2.7°F, while sensors tracked heat, humidity, solar radiation, lighting, and noise.The comparison matters because “cool pavement” is not one single product. Some surfaces reflect sunlight, some encourage evaporation, and some combine several features. Cities must match the material to rainfall, traffic, soil, maintenance capacity, and water availability.
