McAdam, John Loudon (1756–1836)
Scottish engineer who is credited with inventing the so-called macadam road
surface. He proposed that roads should be raised above the surrounding ground,
with a base of large stones covered with smaller stones and bound together
with fine gravel, McAdam applied these ideas when he was appointed surveyor
general of Bristol's roads in 1815. They proved successful, and his views
on road-making were generally adopted after a parliamentary inquiry in 1823.
McAdam was made surveyor general of roads in Britain in 1827.