CaliToday (21/10/2025): In a country where scorching summer temperatures can soar to 50°C (122°F), Qatar is pioneering a bold and visually striking solution to combat a dangerous urban problem: the blue-colored road.
In a large-scale trial, the first of its kind in the world, Qatar’s Public Works Authority (Ashghal) has begun coating asphalt in the capital city of Doha with a special 1mm-thick blue pigment. The goal is to tackle the "Urban Heat Island" effect, a phenomenon where dark-colored city surfaces absorb and radiate intense heat.
The results are already significant. The reflective, heat-resistant coating has been shown to lower the surface temperature of the asphalt by a staggering 15 to 20 degrees Celsius (27-36°F).
This simple-sounding experiment is a high-tech endeavor, blending aesthetics, public safety, and climate sustainability.
The Science Behind the Blue
Traditional black asphalt is a major contributor to the Urban Heat Island (UHI) effect. It acts like a giant radiator, absorbing up to 95% of the sunlight that hits it and then releasing that heat back into the air. This process can make city centers significantly hotter than surrounding rural areas.
In Doha, where the sun is relentless, black asphalt can reach dangerous temperatures, sometimes 20-25°C hotter than the ambient air temperature. This extreme heat isn't just uncomfortable; it increases the risk of burns for pedestrians or children who may fall, degrades the road surface, and increases tire wear.
The new blue coating, developed in partnership with a Japanese company, works in two primary ways:
High Reflectivity: The light blue color has a much higher "albedo," meaning it reflects a significant portion of sunlight (up to 50%) instead of absorbing it.
Heat-Resistant Materials: The 1mm-thick coating contains special heat-reflecting pigments and hollow ceramic microspheres. These microscopic spheres are designed to reflect infrared radiation, further preventing heat from penetrating the asphalt.
The 18-month pilot project was implemented in key, high-traffic areas of Doha, including a 200-meter stretch of Abdullah Bin Jassim Street near the iconic Souq Waqif market, as well as on pedestrian and bicycle paths. Sensors were installed to meticulously measure the temperature difference between the coated and uncoated sections.
More Than Just a Cooler Street
The benefits of this technology extend far beyond a more comfortable walk. Urban planners and engineers see this as a critical climate-smart innovation with a cascade of positive effects.
Reduced Energy Demand: By lowering the ground-level temperature, the blue roads help cool the immediate microclimate. This can lead to a tangible reduction in the demand for air conditioning in adjacent buildings, which in turn cuts energy consumption and, indirectly, greenhouse gas emissions.
Improved Public Safety: Cooler roads are safer roads. They reduce the risk of surface-related burns and make the streets more tolerable for pedestrians and cyclists, encouraging more active forms of transport.
Increased Road Durability: Extreme heat accelerates the degradation of asphalt, leading to cracks and potholes. By keeping the surface cooler, the coating could extend the life of the road, reducing long-term maintenance costs.
Qatar's experiment is a powerful demonstration that even the most ordinary parts of our urban infrastructure can be re-imagined to fight climate change. As cities worldwide brace for increasingly frequent and intense heatwaves, this blend of simple aesthetics and smart science may pave the way for a more sustainable and livable future.
