Provides a transition
between two
tangent lengths of
roadway. (Point
of Curvature at
beginning of curve)
(Point of
Intersection of
tangents) (Point
of Tangency at end
of curve).
•Necessary for gradual change in
direction when a direct point of
intersection is not feasible Ex.
Highways, Interstates,
high speed roads
with constant flow
of traffic.
•When a curve
consists of a single
arc with a constant
radius connecting
the two tangents it is
said to be a
•When a curve
consists of two or
more arcs with
different radius, it is
called a
•A consists of two
arc bending in opposite
directions. Their centers lie on
opposite sides of the
curve. Their radius
may be either equal
or different.
•A curve of variable radius is
known as a . It is
also called a or
. In railways, such
a curve is provided
on both Sides of a
Circular curve to
Minimize super
elevation.
➢For the gradual introduction
➢To introduce gradually
➢To introduce widening gradually
➢To provide comfort for the that
is to enable operation
on
➢To enhance aesthetics of
The following conditions should be fulfilled
while providing a transition curve
•To overcome this force and for
safe travel of a vehicle, the outer
edge of theroadis
above the inner edge.
This is known as
or
.
isprovidedto
achieve the higher speed of
vehicles. It increases the stability
of fast-moving vehicles when they
pass through a horizontal curve,
and it also decreases
the stresses on the
foundation.