- Highway Geometric: This is the branch of the highway engineering which deals with the geometrical elements of the roads like, land of width, formation width, carriage way, side slopes, shoulders, kerbs, sight distance, superelevation and highway curves.
- Land Width: It is total width of the land acquired by the Govt. along the road for the construction and maintenance of the roads. No other buildings by public can be constructed on the land width. Land width depends upon the following factors:
|Types of Camber|
- Gradient: It is the slope provided to the surface of the road in the longitudinal direction for the vertical alignment of the road. There are three kinds of gradients:
A vehicle on ascending gradient
- Ruling gradient is the design gradient, so it is used to design the road in the vertical alignment.
- Limiting and exceptional gradients are provided in the limited stretch of the roads where necessary and in case of the emergencies or exceptional cases when such need arises respectively.
- Minimum gradient is the gradient which is required as the minimum from the drainage point of view in case of the plane areas.
- Sight Distance: Sight distance at any instance is the distance along the centerline of the road which is visible to the eye of a driver at an height of 1.2 m from the road surface such that an obstruction of height 0.15 m is visible to him. The heights of the eye of the driver and the obstruction is standardized by the Indian Roads Congress.
- Stopping sight distance(SSD): SSD is the sight distance which is necessary for a driver to stop a vehicle from the design speed to the 0 speed without any collision with the obstruction on the road. It is also known as the absolute minimum sight distance so this much sight distance is provided at all the cross section of the road.
- Overtaking Sight Distance(OSD): OSD is the sight distance which is necessary for a vehicle running at the design speed to overtake a slower moving vehicle without collision with the vehicles coming from the opposite direction. Generally It is not possible to provide the OSD at every cross section of the road so, it is provided after a stretch of the road.
- Super- Elevation: The outer edge of the road with respect to the inner edge of the road is raised in case of the horizontal curves, this is called super-elevation. Super-elevation is necessary to counter-act the centrifugal force due to the radius of the curve and speed of the vehicle.