Types Of Curve On Hill Road

Hear-pin curves

The curve in an exceedingly hill road that changes its direction through an angle of 180 degrees roughly, downhill on the identical side is understood as the heir-pin curve.

This curve is so-called because it conforms to the shape of a hairpin. The bend so formed at the hairpin curve during a hill road is known as a curve. this kind of curve should be located on a hillside having the minimum slope and maximum slope and maximum stability. It must even be safe from viewpoint of landslides and groundwater. Hairpin bends with long arms and farther spacing are always preferred. They reduce construction problems and expensive protective works. Hair-pin curves or bends of serpentine nature are difficult to barter and may, therefore, be avoided as far as possible.

Salient curves

The curves having their convexity on the outer edges of a hill road are called salient curves.

The center of curvature of a salient curve lies towards the hillside. this kind of curve occurs within the road length constructed on the ridge of a hill. The bend is so formed at the salient curve in an exceedingly hill road called a corner bend.

Salient curves are very dangerous for fast-moving traffic. At such a curve or a corner bend, the portion of the projecting hillside is sometimes cut down to improve visibility. The fringes of the road at such a curve are basically given a parapet wall for the defense of the vehicles from falling down the Hill slope.

Re-entrant curves

The curves having their convexity on the inner fringe of a hill road are called re-entrant curves.

The center of curvature of a re-entrant curves lies far away from the hillside. this kind of curve occurs within the road length constructed within the valley of a hill.

These curves are less dangerous as they supply adequate visibility to the fast-moving traffic. At such curves, the parapet wall is provided just for the security of fast-moving
traffic.