Question

The slope of the road pavement in the longitudinal direction is called
1. superelevation
2. shift
3. gradient
4. camber

Answer 1

Correct Answer - Option 3 : gradient

Gradient:

• It is the slope provided to the surface of the road in the longitudinal direction for the vertical alignment of the road. In other words, Gradient is the rise or fall along the length of road with respect to horizontal. It is expressed as 1 in n (1 vertical to n horizontal) or n% i.e. n in 100.

• There are different types of gradient:
  • Ruling gradient: It is the maximum gradient within which designer wants to design the vertical profile of the road, hence it is known as design gradient
  • Limiting gradient: It is steeper than ruling gradient
  • Exceptional gradient: Discuss above
  • Minimum gradient: It is provided along the length of road for drainage point of view. Minimum gradient for cement concrete drain is 1 in 500.

Gradients for different terrain type:

Terrain type	Ruling gradient	Limiting gradient	Exceptional gradient
Plain and rolling	3.3%	5%	6.7%
Mountainous and steep terrain having elevation more than 3000 m above M.S.L.	5%	6%	7%
Mountainous and steep terrain having elevation not more than 3000 m above M.S.L.	6%	7%	8%