To Beat the Heat, Phoenix Paints Its Streets Gray

[grulla]

THIS TV NEWSREEL ITEM CAUGHT MY ATTENTION THIS MORNING, BUT THE SCI-AM ARTICLE IS DATED 10/3/2021

Daniel Cusick, E&E News
October 3, 2021

Researchers in Arizona have found that urban heat islands made worse by sun-baked asphalt roads can be mitigated by a relatively simple measure. Paint the streets gray.
A study by Arizona State University and the city of Phoenix found that applying a reflective, gray-colored emulsion material to black asphalt resulted in a 10.5- to 12-degree-Fahrenheit drop in average road surface temperatures, while sunrise temperatures saw an average 2.4-degree drop.
“This is exactly what we were hoping for,” Phoenix Mayor Kate Gallego said in a statement. “While there’s work to be done, it’s exciting to see a technology that has the potential to meet the demands of a growing desert city in a world where temperatures are constantly rising.”

Continue reading at: https://www.scientificamerican.com/a...streets-gray/#

[Islander]

What took them so long? I've read other experiments where roads are painted white to reflect rather than absorb heat. I don't pretend to be a scientist but this would appear to be pure logic. Recent temperature extremes in England have melted airport runways, in part because overall, English infrastructure never anticipated temperatures this high. But to prepare for future climate events, why not paint all runways white? Or am I being too simplistic?

[grulla]

In my 42 years of working in the railroad telecom industry, I have sometimes heard of the problem of rails buckling under high temperature, summertime radiant sunlight. But never had I heard, until just recently, of RR workers painting the rails white to help reflect that radiant summer sunshine. https://www.ladbible.com/news/train-...white-20220717