Coquina has also been used as a source of paving material. PERS is made by adding ground up tires to asphalt paving material. Purbeck stone was widely used as a durable paving material. The novelty at the time was use of xilolit plates as a paving material. The tactile paving units can be manufactured in any suitable paving material. This makes sandstone a common building and paving material including in asphalt concrete. Later, tarmac and concrete became the dominant paving material. He developed an inexpensive paving material of soil and stone aggregate (known as macadam).