macadam

noun

1. a macadamized road or pavement.
2. the broken stone used in making such a road.

noun

1. a road surface made of compressed layers of small broken stones, esp one that is bound together with tar or asphalt

n.1824, named for inventor, Scottish civil engineer John L. McAdam (1756-1836), who developed a method of levelling roads and paving them with gravel and outlined the process in his pamphlet “Remarks on the Present System of Road-Making” (1822). Originally, road material consisting of a solid mass of stones of nearly uniform size laid down in layers; he did not approve of the use of binding materials or rollers. The idea of mixing tar with the gravel began 1880s.