There is a big revolution in road construction, as they are many advanced types of machinery and technology available now. Road construction has different ways and methods. Earth roads, gravel roads, asphalt roads, concrete roads, and composite roads are the most common road construction methods. Layers of road There are four layers of a road 1. The surface course This is the upper layer of the road, which makes direct contact with the vehicles. Thus, it provides sufficient friction to the vehicle’s tires and prevents water from draining to the other layers. That’s why asphalt and aggregate cement are used to make the surface course of a road. 2. Base course The surface below the surface or wearing course is called the base course. It is made of dry concrete and or hma. It is also made from crushed sands and stones. 3. Sub-base This is the layer between the base course and subgrade. This is made of crushed stone, concrete, gravel, or recycled materials. It is also called a drainage l