This report outlines the intention of North Sydney City Council's intention to trial TripStop. Seventy five percent of Councilï¿½s footpaths are concrete. This represents an area of 324,200 square metres. Currently within this area there are approximately 2,500 stepped joints caused by the root activity of adjacent trees. Eighteen percent of these steps exceed 25 mm in height. Stepped joints caused by tree root activity account for about 65% of the defects found in concrete footpaths. These figures are a ï¿½snapshotï¿½ ï¿½ no reliable growth models of the vertical displacement of concrete joints are available.