Macadam is a type of road construction that uses small stones or gravel, which are compacted to create a solid surface. Named after the Scottish engineer John Loudon McAdam, this method was developed in the early 19th century and revolutionized road building. The process involves layering crushed stone, allowing water to drain through, which helps maintain the road's integrity. The main advantage of Macadam roads is their durability and cost-effectiveness. They provide a smooth driving surface and are easier to maintain compared to other types of roads. This technique laid the groundwork for modern road construction methods still in use today.