Required Load / Base Depth --- Select Base Depth for Loading --- 0 inches: Pedestrian Use, Erosion Control 2 inches: Cart Paths, ATVs 4 inches: Light Load Driveways, Equine 6 inches: Driveways, Light-Use Car Parks 8 inches: Heavy-Use Car Parks, Emergency Access, Fire Lane 12 inches: Trucking Facilities, Industrial Yards 18 inches: Heavy Loads and Additional Detention 24 inches: Heavy Loads and Additional Detention 36 inches: Heavy Loads and Additional Detention 48 inches: Heavy Loads and Additional Detention 60 inches: Heavy Loads and Additional Detention 72 inches: Heavy Loads and Additional Detention