McAdam, John Loudon (1756-1836), a Scottish engineer, originated the macadam type of road surface. He was the first person to recognize that normal soil, if well-prepared, drained, and protected, can support the weight of traffic without an expensive foundation made of rock. His macadam pavements consisted of small stones packed into layers over dry, prepared soil. The stones provided a smooth surface and kept the soil dry. McAdam was born on Sept. 21, 1756, in Ayr, Scotland. He died on Nov. 26, 1836.
