15.1. A compound curve AB and BC

Try these first

1. 1.

   Define a compound curve.

   Hint

   Think about how curves transition between straight lines.

2. 2.

   What is the formula for tangent length?

   Hint

   Focus on the relationship between the radius and deflection angle.

3. 3.

   What formula do we use to find the tangent length?

   • T = R tan(Δ/2)
   • T = R (Δ/360)
   • T = Δ/R

   Hint

   Think about how the angle affects the tangent length.

4. 4.

   True or False: Compound curves can only be formed with tangents of equal length.

   • True
   • False

   Hint

   Consider the flexibility in design.

5. 5.

   Design a compound curve for a road that connects two straight roadways with the first segment having a radius of 500m and a deflection angle of 40°, and the second segment with a radius of 700m and a deflection angle of 50°. Calculate the necessary tangent lengths and total curves.

   Hint

   Calculate each part one at a time, ensuring angles are correctly input.

6. 6.

   If an engineer has to adjust the curvature due to terrain, how might the calculations change? Discuss what parameters might be affected.

   Hint

   Think of how terrain affects road construction.