A major U.S. city has miles of colonial clay brick sidewalks that were installed generations ago. Over the years, the sidewalks have become very uneven creating trip hazards for everyone walking on them. The problem is further exasperated by shade trees planted every 20 to 30 feet along the sidewalk. As the trees have grown their branches keep the sidewalks shaded, providing a reprieve from the hot sun in the summer months. But their roots have pushed the bricks up, creating uneven walking surfaces and slippery wet areas.
Instead of repairing the uneven bricks and trimming the tree branches, the city chose to hang permanent “Caution: Watch Your Step” signs around the trunk of each tree. The signs have been in place for more than five years now, but nothing has been done to repair or replace the sidewalks. While these signs show that the city is aware of the problem, they do not effectively eliminate the hazard.