Introduction of Highway (Topic # 01)

Introduction of Highway 

Road Structure

 When we cut the road in vertical plan, different parts of the road are visible which are as follows.

·         Sub grade

·         Sub base

·         Base

·         Surfacing

Components of road structure

Sub Grade

This is the natural surface of the earth. On which the road is built. Its surface is usually kept 60 cm (2 feet) above ground level for Rainwater could not reach the road surface. If the road needs to be built in the cutting section, then the sub-grade level is below to the ground level.The strength of the road depends largely on it.

Sub Base

It is not an integral part of the road but when the sub-grade is weak then the addition of stone and gravel is provided to strengthen the road is called sub-base.

Base

It is an integral part of the road. It transfers safely to sub-base or sub-grade while bearing the load of traffic moving on the road. The strength of the road depends on it.

Surfacing

This is the upper part of the road that makes the road surface smooth. Also makes the road surface non-absorbent. The type of road is determined based on the material used in the same section.

Types Of Roads

Roads are mainly divided into two groups:

·         Unpaved roads

·         Paved roads

Unpaved Roads

This type of road is usually built in villages. The natural soil of the area is used to make these roads. For a good road, the ratio of clay to sand should be 65:35 If the natural land is not improved, then the process of soil stabilization is considered before the road is built. In this process the ratio of clay and sand is corrected. Or cement and other chemicals are added to the soil. Then the road is built from mud.

Paved Roads

These roads are good. The major cities and towns of the country are connected by these roads. There are two more types of paved roads.

        i.            Bitiuminous Road

   Sub-bases and base-layers are laid after the preparation of sub-grades to make such roads. Which is made of stone and gravel. Bitiumen is used in the base layer.And the last layer is the tsarfking which consists of fine stones and Bitiumen. These roads are also called flexible roads.

      ii.            Concrete Road

Cement is used in the construction of this type of roads. These roads are longer lasting and do not require much attention to repair. It costs more to build these roads.these Roads are also called rigid road

Technical Terms

The following technical terms should be used in road construction :

Land Width

Total road ownership is called land width, it is also called right of way.

·         Formation Width

 The width of the road on the prepared surface of the road is called the formation width. This includes the solid part and the width of the shoulder.

·         Carriage Way

The paved part of the road on which high speed traffic flows, this width of the road is called the metallic width of the road. It is also called the carriageway

·         Shoulder

The surface left on the sides of the paved part of the road is called the shoulder. This part of the road is used to repair a vehicle malfunction or in other emergencies.

·         Side Slope

  Slopes are provided on the sides of the road from the level of formation to the natural ground level to keep the road safe. This is called side treatment.

·         Gradient

The slope along the length of the road is called the gradient.

·         Separator

Lines laid to divide the road into two or more sections along the length are called Separator.  It is sometimes made of concrete or masonry. If the road is used to separate different types of traffic, it is called a grade separator.

 

Road Structure

·         Foot Path

  A parallel walkway on the side of the road is called a footpath. It is 1.3 meters (٤ ft) wide.

Bicycle Track

The side of the road is designed for cyclists. The road is called a bicycle track and is two meters (four feet) wide.

Kerb

An obstacle to a paved road and sidewalk is called a kerb.

Camber

  The slope facing the width of the circuit is called the camber. The purpose is to remove rainwater from the road surface

Road structure

Different Types Of Road

·         Crete Way

·         Urban Road

·         Country Road

·         Service Road

Crete Way

Low-lying roads are sometimes paved under the wheels of vehicles. Such roads are called concrete roads.

Urban Road

A road built in an urban area is called an urban road.In addition to the paved sections in this road, foot path and separators are also made.

Country Road

A road built outside the urban population is called a country road

Service Road

Small roads are made parallel to the main road which is connected to the main road at some distance.  The purpose of this road is to reach the side building without disturbing the traffic on the main road.