Macadam

Have you ever seen a road made out of little rocks that are all stuck together? That's called macadam!

Macadam is a type of road surface that was invented a long time ago by a man named John McAdam. He found that if he made a road out of small rocks that were all the same size and shape, and then he smashed them down really hard, it would make a really strong road that wouldn't get muddy and mushy when it rained.

The rocks used in macadam roads are called aggregates. The aggregates are spread out in layers and then pressed down with heavy machines. This makes the road nice and smooth and strong. Macadam roads are also really good for places where it gets really hot in the summer because they don't melt like some other types of roads.

Macadam roads can come in all different colors depending on what kind of rocks are used. Some are gray, some are brown, and some are even red or green!

So, next time you're driving down a road and you see little rocks all stuck together, remember that's macadam!