The document discusses different types of curves used in road design including horizontal curves, vertical curves, simple curves, compound curves, reverse curves, transition curves, sag curves, and crest curves. Horizontal curves provide a gradual turn between two straight sections of road, while vertical curves allow gradual changes in elevation between two sloped roadways. Each type of curve is designed to ease transitions and avoid sharp turns or changes in grade.

3. A line which is not straight with
no sharp edges is called a curve. It
is a smoothly flowing line.

4. 1.Horizontal Curve
2.Vertical Curve

5. A horizontal curve provides a
transition between two tangent
strips of roadway, allowing a
vehicle to negotiate a turn at a
gradual rate rather than a sharp
cut.

7. 1.Simple Curve
2.Compound Curve
3.Reverse Curve
4.Transition Curve

8. A simple arc
provided in the
road to impose a
curve between
the two straight
lines.

9. Combination of
two simple curves
combined together
to curve in the
same direction.

10. Combination of
two simple curves
combined together
to curve in the
opposite
direction.

11. A curve of constantly
changing radius, used
to connect a circular
arc to a straight line.

12. A vertical curve provides a
transition between two sloped
roadways, allowing a vehicle to
negotiate the elevation rate
change at a gradual rate rather
than a sharp cut.

14. 1.Sag Curve
2.Crest Curve

15. Sag Curves are
those which
change the
alignment of the
road from uphill to
downhill.

16. Crest Curves are
those which change
the alignment of
the road from
downhill to uphill.