http://www.ext.vt.edu/pubs/trees/430-028/430-028.html

Alternatives to pavement repair involve the initial use of, or replacement with, other paving materials. One alternative is
landscape pavers, porous concrete pavers that can also be used for parking lot surfaces instead of solid asphalt or concrete. A
second alternative, still being developed in California, is the use of rubber sidewalks. Rubber sidewalks, made from compressed,
recycled crumb rubber (mainly from recycled tires) provide malleable paving surfaces that give way to invasive tree roots.
Rubber sidewalks are cost-effective and aesthetically acceptable alternatives to conventional paving materials. Though rubber
sidewalks may bend a bit out of shape in response to aggressive roots they do not create abrupt edges over which pedestrians
might trip, and they provide a softer surface should someone fall on them.

http://www.google.com/search?sourcei...er+sidewalk%22