All of the pavements assessed displayed crossfalls and longitudinal grades that are considered to be
typical of PICP (0.5 % to 2.0%). Typically, permeable pavements will not build-up sediment loads
in a uniform manner for various reasons and most likely it will tend to exhibit zones where sediment
build-up is more concentrated. For this reason a testing regime was devised ensure that infiltration
tests would be conducted in both high and low sediment load areas. Where possible each
pavement was tested at the lowest and highest elevations and, in some cases, at intermediate positions.
Tests were also conducted below or adjacent to trees so that the effects of leaf litter could be
evaluated.