How cities can counter overheating in summer simply with light colored roofs and streets

This has already been suggested several decades ago! Why does it take so long to implement it?

It would most likely help to reduce the heat island effect in urban areas. This heat island effect also messes up the measurement of air temperatures, because many weather stations are located in urban areas.

"... A full suite of interventions could reduce peak temperatures up to 5 degrees — but make it feel up to 15 degrees cooler ...
Cool Roadways Partnership of about 30 U.S. cities — a dozen of which (like L.A. and Phoenix) are resurfacing roads in pilot projects of up to 200 blocks. ..."

How cities can mitigate heat waves (The article is not really recommendable. It is loaded with ideology and propaganda and it is very narrowly focused)