Cool Routes app plots shady walks in arid Arizona

A new app created by Arizona State University researchers lets users map out the shadiest walk to their destination to help them avoid the effects of extreme heat, which can reach deadly temperatures in the Southwestern summer.

As Joe Rojas-Burke explains in ASU News, "Cool Routes, an online tool developed by Ariane Middel and colleagues in The SHaDE Lab at ASU, chooses paths based on forecasts of mean radiant temperature, a measure of the total heat load experienced in a given location, including reflected heat and sun exposure."

The app, which updates itself hourly with weather data, uses more than just air or surface temperature, taking into account reflected heat and sun exposure. "In sun-blasted Phoenix, mean radiant temperature can exceed 150 degrees F in full sun but drop below 100 in the shade. Shade can make a real difference on people’s heat exposure on a hot, sunny day." In tests, the app identified cooler alternatives for 70% of trips and lowered the experienced heat load by about 4.5 degrees on average.

According to Rojas-Burke, "The current version covers ASU's Tempe campus, but it is an open-source framework that can be put to work in other cities to support walking, biking and public transit use."