4.6. Example 2.6

Try these first

1. 1.

   What is the formula for calculating the tangent length?

   Hint

   Think about the relationship between the radius and the angle.

2. 2.

   Define the term 'Chainage'.

   Hint

   Consider how we measure distances on roads.

3. 3.

   What is the formula for calculating the tangent length?

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

   Hint

   Remember to halve the deflection angle!

4. 4.

   The deflection angle of a curve is always:

   • True
   • False

   Hint

   Consider its role in designing the curve.

5. 5.

   Given a deflection angle of 70 degrees and a radius of 100 m, calculate the tangent length and length of the curve.

   Hint

   Break down the deflection angle into half for your calculations.

6. 6.

   If two tangent roads meet at a chainage of 1500 m with an angle of intersection of 90 degrees, find the chainages at the point of curve if radius is 40 m.

   Hint

   Apply the same methods we practiced in class for consistent results.