John Loudon McAdam | |
|---|---|
 Engraving of McAdam at the British Museum | |
| Born | 23 September 1756[1] Ayr, Scotland |
| Died | 26 November 1836 (aged 80) Moffat, Dumfriesshire, Scotland |
| Nationality | Scottish |
| Citizenship | Scottish |
| Occupation | Engineer |
| Engineering career | |
| Significant advance | "Macadamisation" |
John Loudon McAdam (23 September 1756[1] – 26 November 1836) was a Scottish civil engineer and road-builder. He invented a new process, "macadamisation", for building roads with a smooth hard surface, using controlled materials of mixed particle size and predetermined structure, that would be more durable and less muddy than soil-based tracks.
Modern road construction still reflects McAdam's influence. Of subsequent improvements, the most significant was the introduction of tar (originally coal tar) to bind the road surface's stones together, "tarmac" (for Tar Macadam.)