Fundamentals of Road Design

As roads connect people and vehicles across different locations, it is important that they are designed to tolerate loads. Learners must understand the fundamental engineering design processes and standards followed in the civil industry when constructing roads.

This week will cover

• Why we design roads
• Importance of a holistic road network
• Various verticals and departments involved in roadway design
• Decision making process followed by highway designers

Before roads are constructed, the site and surrounding land is surveyed to determine if it is suitable and safe. For engineers working in the civil industry, it is important to understand the parameters surveyed, how the data is obtained, and how it is interpreted to make decisions.

This week will cover

• Topographical data, traffic data, axle survey data
• Design alternatives and its evaluation
• Understanding existing design criteria and proposing design standards.

Roads have a horizontal and vertical profile, each having their own design considerations. It is important to understand the basics of horizontal road design, and the tangents, spirals, and curves involved in it.

This week will cover

• Fundamental concepts involved in horizontal design
• Objects in horizontal alignment: Tangent, spiral and curve
• Super elevation and its importance in highway design
• Extra widening at curve locations
• Critical checks for an efficient highway design

The pavement layer of roads is essential in safely and efficiently distributing the load of passing vehicles to the soil layer below. It is important for learners to understand the basics of pavement design, and the two main types - rigid and flexible pavements.

This week will cover

• Fundamentals of pavement design
• Annual traffic calculation
• Rigid pavement design
• Flexible pavement design

Highway roads have different elevations and alignments in their vertical profile. The vertical design of a road undergoes much engineering and consideration to ensure it is safe for vehicles to travel on. It is important for learners to understand vertical design consideration when developing roads.

This week will cover

• Fundamental concepts of vertical design
• SSD check on vertical profile
• Criteria for fixing vertical design profile
• Selection of cross sections based on roadway conditions
  
• Embankment slope considerations
  
• Earthwork volume calculations