A Cooler Road Can Warm Its Neighbors
Dark asphalt absorbs much of the sunlight that reaches it, then releases that energy as heat. Pale pavement reflects more sunlight, so its surface can stay cooler. That can reduce one source of heat near street level—but reflection changes where the energy goes, rather than making it disappear.
Where the Reflected Sunlight Lands
Sunlight bouncing off a road may strike a nearby wall, parked car, or person. A building can absorb that energy and warm up; pedestrians may feel more radiant heat even when the pavement itself is cooler. The effect depends on the street’s geometry, the sun’s angle, and the materials around it. A wide, open road and a narrow street lined with buildings do not send reflected light into the same places.
The Tradeoff Is About the Whole Street
A reflective surface can help limit heat stored in pavement, but judging its value by road temperature alone misses the neighborhood-scale exchange. Designers need to consider where reflected light travels and whether nearby shade, trees, or building surfaces can absorb or block it. The useful question is not simply how much sunlight a road reflects, but who or what receives it next.
