Tarmac (short for tarmacadam, a portmanteau for tar-penetration macadam) is a type of highway surface, pioneered by the Scotsman John Loudon McAdam in around 1820. Strictly speaking, Tarmac refers to a material patented by E. Purnell Hooley in 1901. The term is also used, with varying degrees of correctness, for a variety of other materials, including tar-grouted macadam, Tarvia, bituminous surface treatments and even modern asphalt concrete. Origins Macadamized roads were adequate for use by horses and carriages or coaches, but they were very dusty, subject to erosion with heavy rain and did not hold up to higher speed motor vehicle use. Methods to stabilize macadam roads with tar date back to at least 1834, when Henry Cassell patented "Pitch Macadam". This method involved spreading tar on the subgrade, then placing a typical macadam layer and then sealing the macadam with a mixture of tar and sand. Tar-grouted m

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