The variation in soil structure has a great influence on the grounding grid performance. This influence can be measured in terms of ground resistance, touch and step potentials. This paper presents a comprehensive experimental study for the influence of adding driven rods on the performance of grounding grids. The study is applied on three constructed scale models. The models have been performed to simulate a single-, double- and triple-layer soils. A comparison between results obtained experimentally and that computed by mathematical equations is introduced.