Re: the May 7 column "Test aims at finding best kind of road for Tucson."
Cooler road surfaces are imperative with the heat extremes being experienced throughout the southwest, but more asphalt is the wrong path. Many decades of road surface experience with concrete pavements and cement-finishes on roads provide convincing evidence to go this route. It is an integral component of how to reduce urban heat islands, energy costs, and air pollution, with high-albedo (sun-reflecting) roof tops, and street shade tree canopies, being the other two major opportunities. A picture is worth a 1000 words, and this is certainly the case with the thermal image of a road pavement at Mesa, Arizona, where the 20 degree temperature difference between the asphalt pavement at rear and the concrete pavement in the foreground is striking: http://wikipave.org/index.php?title=File:Green13.png
Michael Totten
Denver, Colo.
Disclaimer: As submitted to the Arizona Daily Star.
