City streets can become massive heaters during hot, sunny weather, which is exactly the opposite of what is needed. The intensity of heat can burn bare feet and the paws of our pets.
It can also contribute to heightened ambient temperatures. This is a phenomenon referred to as the “heat island” effect, in which heat found within cities is greater than that of surrounding areas. Tests are underway in Los Angeles to moderate the “heat island” effect by painting roadways a lighter colour.
On a hot day in Canoga Park, a residential neighbourhood of Los Angeles, the pavement measures 93F degrees. After being coated with a light grey sealant, the pavement measures a much more tolerable 70F degrees. The lighter colour reflects heat, rather than absorbing it.
The drop in roadway temperature influences the ambient temperature, making it cooler for people living along the street. Not only does this provide greater comfort and healthier conditions for the residents, it also lowers the rate of energy consumption by reducing the reliance upon air conditioners and fans.
The special coating is intended to last for seven years between applications, which are estimated to cost $40,000US per mile. I guess the locals can brag about living on the “coolest” street in town.