The results of an experimental road research project are presented which demonstrate the existence of spatial repeatability and show patterns of axle impact forces along a pavement. As part of the project, a section of highway near Paris, France, was instrumented with 18 weigh-in-motion sensors. Data was collected for a large number of vehicles over fourteen days between June 1994 and May 1995. For all the vehicles, the impact factors were calculated and typical graphs are presented which show the variation of impact factor with distance along the sensor array. Mean impact factors and coefficients of variation are also presented and differences between steel and air suspensions are highlighted. The influence of vehicle speed on maximum impact factor is also considered.