Morocco Tests 'Sponge' Pavement for Cooler, Greener Roads

Morocco is testing a 'sponge' pavement that drains water and cools itself through evaporation. Parts of Marrakech and Agadir are testing grounds for this surface, deemed environmentally better than black asphalt. The idea aims to reduce urban heat islands, improve drainage, filter pollutants, and cool through evaporation.

Conventional black asphalt reaches high temperatures, creating urban heat islands. In an Arizona pilot, conventional pavement reached 152°F, while cool surfaces remained 10-16°F cooler. Permeable pavement allows water to enter a stone base, storing moisture that can evaporate, cooling the surface.

Morocco’s experiments are part of the 'Marrakech Sustainable City' program, launched in 2023, focusing on climate resilience, mobility, and energy efficiency, with $9.5 million in funding. The program aims to benefit over 1 million people.

Benefits include reduced runoff, improved traction, and cooler microclimates, potentially lowering demand on vehicle air conditioning. However, permeable pavement requires maintenance to avoid clogging and is suited for low-traffic areas.

Similar projects, like Spain’s 'LIFE HEATLAND', used light-coloured pavement to reflect sunlight, reducing temperatures. Cities must match materials to local conditions. Morocco’s approach focuses on evaporation, highlighting the need for tailored solutions.