Type 1 MOT also known as DOT Type 1, is a 40mm to dust sub-base material which is crushed to provide a stable sub-base for road surfaces and pathways and other various building projects. MOT standard sub-base can consist of both primary and recycled materials. The mixture of solids and fines ensures minimal voids in the sub-base material when compacted, giving a strong load bearing layer with a suitably flat surface.