RISE or falls along the length of the ROAD with respect to horizontal.Expressed as ‘1' vertical unit to 'N' horizontal units.Types of Gradient:i) Ruling gradient: The gradient is fixed in such a way that maximum power developed by the engine is equal to the power required to overcome the RESISTANCE to the motion on the grade at design speeds.ii) Limiting gradient: A gradient steeper than the ruling gradient which may be used in restricted length, where the ruling gradient is not possible.iii) Exceptional gradient: A gradient steeper than the limiting gradient which may be used in very short STRETCHERS only in an exceptional case.iv) Floating gradient: The gradient on which a motor vehicle moving with a constant speed continues to descend with the same speed without any application of power brakes is called floating gradient i.e the vehicle does not require any tractive effort to maintain the specific speed.∴ Limiting gradient is the steepest gradient permitted on roads in ordinary conditions and in some extraordinary situations it may be unavoidable to provide STILL steeper gradients at least for short stretches and in such cases, the steeper gradient up to exceptional gradients may be provided. The ruling gradient or the design gradient is the gradient with which the designer attempts to design the vertical profile of the road.Note:TerrainRulingLimitingsExceptionalPlain/Rolling3.35.06.7Hilly5.06.07.0Steep6.07.08.0