Road Estimation

Estimation of earthwork of roads by using different methods and a comprehensive detail of cross-section of Road Estimation

Road Estimation


This article comprises the complete detailing of a cross-section of roads and estimation of excavation volume. It is expected from civil Engineers that they should be dexterous in the estimation of buildings. Likewise, transportation Engineers should be proficient in the estimation of roads. This article will help a lot to those who want to learn the estimation of roads because it comprises the background information, associate terminologies, and cross-section drawings of roads. Apart from this, by using different methods, we will be estimating the excavation volume and also correlating the graphical representation of the reduced level of natural surface.

History of the Construction of Roads

 Most people don’t pay attention to history or background information about the construction of roads. However, we use to drive on Road. As long as ago (2500 BC), a road was built in the era of Egypt, and that is considered one of the earliest construction of roads in history. This Road leads to the Egyptian Pyramid, and the dimensions were 1000 yards in length and 60 ft width. It was used for pedestrians, not for traveling purposes.

There were some roads constructed by the people of America in the middle ages, but those roads were not like the wheel constructed by older people, as shown in the figure.

Road Estimation

Despite this, they played a very important role in the history of the construction of roads. The roads were constructed by using dirt material, and that’s proved beneficial material in encountering the stresses. These constructions of roads are still used in some countries. Further, as long as ago (700 A.D.), the Road was built in Iraq by using “tar.” This material was durable and had outstanding strength properties. This material was capable of withstanding the increasing traffic between middle east countries.

Nowadays, the roads are made of a variety of materials like concrete, cobblestones, etc. Modern construction of roads doesn’t involve geographical hurdles, and the materials are very durable and sustainable. The material for pavement is provided by using advanced equipment. Road Estimation.

These roads are designed for the use of Vehicles and pedestrians. The underground drainage system before the construction of the Road is properly designed

Related Theory

In transportation engineering, the various type of pavements is differentiated based on cross-section material of roads.

Pavement has three main types;

  1. 1- Typical flexible pavement
  2. 2- Reinforced cement concrete (R.C.C.) pavement
  3. 3- Triple surface treatment pavement (T.S.T.)

Typical flexible pavement

This type of pavement is generally used for city roads and other normal purposes, where roads are no more important. The cross-section details are shown in the figure.

Reinforced Cement Concrete (R.C.C.) pavement

This type of pavement is used where the traffic is high and needs more strength in the construction of roads—for example, highways and motorways.

Due to contraction and expansion, joints are provided within R.C.C. slab pavements. Also, to avoid vertical deflection, steel reinforcement is provided between two adjacent slabs so that one end of the slab is fixed and the other end is free.


Triple surface Treatment (T.S.T.) 

This low-quality pavement is generally used in villages or on the left side of lanes. This purpose is just to provide parking to the vehicles. The cross-section detail is shown in the figure. Road Estimation

As earthwork and the calculation of base material are usually estimated separately because of each sub-layers thickness.


Drawing plan of the Road


A road plan gives us information regarding the number of lanes, fence, and position of signs and poles, etc. the typical plan of the Road is shown in the figure.



The earth’s natural surface level in the construction of roads is not usually the same reduced level, so a single layer of earthwork is provided; it is called sub-grade.

Calculation of volume of the Road Bank

The cross-section of the bank of Road is trapezoidal, so by selecting the unit length, we calculate the volume of the road banks. Road Estimation

Methods of Estimation

Different methods of estimation of excavation volume for roads

Mid Sectional Area Method

     Area= A= Bdm + Sd2

         Volume = Area × length

Mean section area method

Area1 = Bd1 +Sd1

   Area2= Bd2 + Sd2

                                   Mean Area =

                                   Volume = Mean area × length

Primordial Formula Method

Area = [ B () + S  ]  

                                  Volume = Area × length

Estimate the Volume of Road

Let’s estimate the volume of road construction for the given data

Given data

  • Reduced level of the ground along the centerline of Road at 25m is given below
  • The foundation level at a running distance of 300m = 106m
  • the downward gradient of road 1 in 150 up to running distance 400 and after that it becomes 1 in 100
  • formation width B= 10m
  • side slopes are 2:1



Cutting and filling detail of Required data by using graphical interpretation.


Midsection Area Method

Area= A= Bdm + Sd2

Volume = Area × length


Mean Section Area Method


Prismoidal Formula Method

Area = [ B () + S  ]

Volume =  Area ×  length



From the above article, it is concluded that as for Civil engineers, it is important to understand the estimation of material for buildings. Similarly, transportation engineers must understand the estimation of roads as it is one of the major projects in the construction industry. While during the calculation, the study of the reduced level is very important to comprehend the estimation. if the reduced level of the natural surface level is not varying. Using the above formulas, the excavation volume can be calculated. But if the reduced level varies after a certain distance, then we have to analyze the running distance data, reduced level of natural surface and required reduced level of the floor to cut and to fill purpose graphically.