Rubber Sidewalks

Here's a great idea someone came up with: rubber sidewalks.  It looks like a number of cities, including Washington DC, have begun installing rubber sidewalks.

There appears to several reasons for this.  First, tree roots can damage normal concrete sidewalks, but apparently rubber sidewalks do not constrict tree roots.  Second, rubber sidewalks are made from recycled tires so they are friendly to our environment.

The third reason is what interested me: rubber sidewalks cause less pounding on the body than concrete sidewalks.  Concrete sidewalks are one of the hardest surfaces to walk on; when I walk, I usually walk on the asphalt road when I can.  I would love to see rubber sidewalks spread and make it easier for people to exercise.