QUESTION
Objective Question
The perpendicular offsets from a tangent to the junction of a transition curve and circular curve
is equal to
Answer
( Option D)
4 × shift 'S’
Solution
The perpendicular offset y at any distance x measured along the tangent line from the starting
point of a cubic parabola transition curve is given by:
Where:
L = Total length of the transition curve
R = Radius of the circular curve
At the junction point where the transition curve meets the circular curve, the distance x
becomes equal to the total length of the transition curve.
The lateral shift (S) introduced to accommodate the transition curve is mathematically defined
as:
