There is an established relationship between pavement deflection and pavement
condition as expressed by repetitive loading of it by vehicular traffic. As the
cumulative traffic increases with resulting damage to the pavement, higher
deflections will be observed as its structural condition deteriorates. Deflection
remains generally stable until the ‘investigatory condition’ is reached where
deflections will start to increase with applied loading and cracks will begin to
appear. The ‘failed condition’ is arrived at when rapid increases in deflection are
experienced