While footpaths can be 75mm, driveways deal with substantially more weight and traffic. The recommended thickness of a driveway slab will vary depending on the type of vehicles regularly using the driveway. Driveways slabs be a minimum of 125mm thick. Driveways of 100mm will usually sustain damage if used by heavy vehicles. Steel reinforcement or mesh will not increase the load capacity of your driveway – it simply provides crack control. The thickness of the concrete is what determines the load capacity. However, improper construction can lead to crushed concrete and structural failure of the driveway.