2.30. Explain the following terms for a simple circular curve: (i) Back and forward tangents, (ii) Point of intersection, curve and tangency, (iii) Deflection angle to any point, and (iv) Degree of curve

Try these first

1. 1.

   What is a back tangent?

   Hint

   Think about the direction before entering a curve.

2. 2.

   Define point of intersection.

   Hint

   Consider where the straight roads connect to form a curve.

3. 3.

   What does the back tangent refer to?

   • Line after the curve
   • Line before the curve
   • Middle of the curve

   Hint

   It is the line you are coming from.

4. 4.

   True or False: The degree of curve helps in determining the maximum safe speed of vehicles on a curve.

   • True
   • False

   Hint

   Think about how fast you can drive through a sharp turn.

5. 5.

   If a circular curve has a degree of curvature of 5 degrees, what is the radius of the curve?

   Hint

   Use the relationship that connects radius and degree of curvature.

6. 6.

   With a deflection angle of 45 degrees, calculate the distance from the PI to the tangent point if the radius is 100 m.

   Hint

   Think about the geometry of circular curves.