Reflective pavements can improve visibility at night.

While high-albedo (reflective) pavements can cool temperatures during the day, reflective pavements can improve visibility at night. Consider a pedestrian near a street lamp crossing the street at night. The pedestrian is obviously illuminated by light from the street lamp. However, the pedestrian is additionally illuminated by light from the street lamp that is reflected off the pavement. The geometry is drawn in the figure above.

We estimate, for a subject S (of area A_s), that the ratio of light from the street lamp that reflects off a pavement ("Reflected light") to that light directly from the street lamp ("Direct light") is approximately equal to the pavement's reflectivity in the visible spectrum ("Visible reflectivity"). In other words, if the reflectivity is 10%, an 10% additional light will illuminate the pedestrian from the street lamp after reflecting from the pavement. If the reflectivity is high, the amount of street lighting could be reduced to achieve the same illumination thus saving energy.