Macadam road surface
Firme de macadán
- Date
- 1816-1820 · confidence high
- Place
- Bristol, England, United Kingdom
- Credited to
- John Loudon McAdam (and Thomas Telford, an alternative method)
- People
- 👤 John Loudon McAdam1756–1836
- Field
- Tools
What it is
A road surface of layers of uniformly sized crushed stone, cambered for drainage, which compacted under traffic. Cheap and durable, it revolutionised roads and stagecoach travel before the railway.
McAdam applied the method as surveyor of the Bristol roads from 1816 and published it in 1820.
What it led to
- The turnpike road network and fast stagecoaches
- Fast mail coaches and regular services
- Tar-sealing ('tarmac', 1902) and roads for the automobile
- Road engineering as a speciality
Built on
- Roman roads
- Trésaguet's methods (France, 1775)
- Stone crusher
Made possible
- Autostrada dei Laghi (first toll motorway)21 de septiembre de 1924
- Tarmac (tar-bound macadam)
- Steam roller (Aveling, 1865)
- Bicycle and motor car (practical viability)