Interlocking block layer, sand bedding layer, subgrade, and sub-base. 1. The interlocking block layer is the distinguishing layer of the interlocking block pavement from other road structures. It not only serves as the wear layer but also as the structural layer (overall load distribution), with blocks that can be shaped into various patterns to beautify the environment. 2. The sand bedding layer's function is to level the subgrade and provide the necessary conditions for a tight interlock for the surface layer. 3. The subgrade and sub-base are almost identical to those of general asphalt pavements. 4. Edge restraint is essential; it limits the lateral displacement of blocks under the action of traffic loads to ensure interlocking between the blocks.