2.70. A parabolic vertical curve is to connect a –2.2% gradient to a +1.9% gradient...

Try these first

1. 1.

   What is a vertical curve?

   Hint

   Think of how hills are formed in a road.

2. 2.

   Why do we need vertical curves?

   Hint

   Consider driver comfort and visibility.

3. 3.

   What is the required length of a vertical curve connecting a -2.2% gradient to a +1.9% gradient?

   • 10.14 m
   • 14.28 m
   • 20.0 m

   Hint

   Review the gradient transition designs.

4. 4.

   True or False: Vertical curves have no effect on driver visibility during elevation changes.

   • True
   • False

   Hint

   Consider what happens on steep climbs or descents.

5. 5.

   A parabolic curve is to be designed between a -1% gradient and a +3% gradient on a highway with a design speed of 100 km/h. Calculate the minimum length of the vertical curve required.

   Hint

   Check how speed and gradients dictate curve length.

6. 6.

   Discuss the effects of neglecting vertical curves on highway designs in terms of safety and comfort.

   Hint

   Use examples of sharp inclines or declines.