It is encouraging to notice that, little by little, human beings are becoming more important than cars. Good sidewalks stimulate walking, thereby improving people’s physical and mental conditions. The cardiovascular and weight-management benefits of walking are now beyond doubt. If towns and cities have sidewalks, there is no need for other trails.

Nevertheless, the June 25 Health Beyond Health Care article “Step by step, cities make ways for walking” failed to mention that sidewalks need to be supplemented by shade and lights to be effective. Sidewalks without shade are of no use during summer days when the sun hurts. Sidewalks without lighting are not recommended after sunset, as lights deter criminals.

There are many examples, both in the United States and the rest of the world, of sidewalks with trees, whose branches and leaves form protective canopies and where walking is pleasant, even during high-heat days. A year ago, my wife and I had a delightful experience in Seville, Spain, strolling several miles along a sidewalk parallel to the Guadalquivir River on a 90-degree day. We also enjoyed attractive footpaths in Santiago, Chile, well-lighted and covered with natural tree awnings. In short, to create the best conditions for walking, I suggest taking into account SLS: sidewalks, lights and shade.

Samuel Gustavo Levy, Rockville