Factors affecting Geometric Design of Road
To design a road, it involves the terrain and other features to be considered. Some of the important features are width of the road, friction, camber, Sight distance, Horizontal Alignments and Vertical alignments
The important features in geometric design road are
Cross-Sectional elements: Width of the road, friction, camber etc
Sight distance: Stopping Sight Distance (SSD), Overtaking Sight Distance (OSD), Intermediate Sight Distance (ISD)
Horizontal Alignments
Vertical alignments
These geometric features of the road play an important role in traffic flow characteristics.
Factors affecting the geometric design
Design speed
For every road, we specify a speed limit above which the road will be designed with the design speed. For example National Highways have a design speed of around 80 kmph.
Topography
Based on the terrain and percentage of slope, the geometric features too change.
Other factors
Traffic keeps changing from morning to evening
Vehicle type
Environmental: If it is designed for a rain prone area then we have to provide a higher camber.
Cost of excavation