In a similar vein, I've sometimes wondered why roads aren't a lighter color.
I drive on some recently paved roads and they were all paved black. Seems that if we mixed the asphalt with a small amount something light and unwanted (plastic bottles?), but light in color, we could put a dent in both the garbage problem and the heat absorption problem.
Doesn't have to be full white, as that would glare worse than dark black. But a few shades lighter could help some.
> In a similar vein, I've sometimes wondered why roads aren't a lighter color.
Years ago the freeway maintainers were applying rubberized asphalt to the freeways in the metropolitan Phoenix area. The newly-rubberized freeways were very, very black. "Brilliant, just brilliant", I thought.
Some time later I read that while rubberized pavement gets hotter than plain asphalt during the day, it cools much, much quicker at night. The article had infrared aerial photos of the Phoenix metro area pre-rubberized freeways and post-rubberized freeways. Before the project the freeways were all lit up. After the rubberized surface was applied, the freeways were entirely black on the infrared photos.
Rubberized asphalt, applied to Valley freeways to
minimize noise, has an unintended benefit: It's cooler
at night than other pavement, according to the Arizona
Republic.
That's because air holes constitute 20 % of rubberized
asphalt, said Kamil Kaloush, an assistant professor of
civil and environmental engineering. Those pockets of
air allow heat to escape, something that dense concrete
can't do.
I drive on some recently paved roads and they were all paved black. Seems that if we mixed the asphalt with a small amount something light and unwanted (plastic bottles?), but light in color, we could put a dent in both the garbage problem and the heat absorption problem.
Doesn't have to be full white, as that would glare worse than dark black. But a few shades lighter could help some.