Road curve
Road Curves are regular bends provided in the lines of communication like roads, railways etc. and also in canals to bring gradual change of direction. Curves provided in the horizontal plane are known as Horizontal Curves. They may be circular or parabolic. Circular Curves provided on roads are classfied into 4 types:
- Simple Curve
- Compound Curve
- Reverse or Serpentine Curve
- Deviation Curve
Simple Curve
A curve is said to be simple when it has same radius throughout and consists of single arc of circle with two tangents meeting at actual point of intersection of roads. In the diagram shown B is the actual point of intersection of roads. [1]
Compound Curve
A compound Curve Consists of two or more simple curves having different radii but bending in same direction and lying on same side of common tangent. In the diagram shown MN is the commom tangent.
Reverse Curve
It is also called as serpentine curve and is just reverse of compound curve. In this type of curve, two simple curves bent in opposite directions on different sides of common tangent.
Deviation Curve
Deviation curve is simply combination of two reverse curves. It is used when it becomes necessary to deviate from given straight path in order to avoid intervening obstructions such as building, places of worship, river etc. [2]