18. Vertical Alignment - 2

Try these first

1. 1.

   What characterizes a valley curve?

   Hint

   Think about the shape of a 'U'.

2. 2.

   What factor greatly affects visibility on valley curves at night?

   Hint

   What do drivers depend on when driving at night?

3. 3.

   What type of curve is a valley curve?

   • Concave
   • Convex
   • Linear

   Hint

   Think about the shape that resembles a valley.

4. 4.

   True or False: Valley curves are only a concern during the daytime.

   • True
   • False

   Hint

   Consider how visibility changes at different times of day.

5. 5.

   A road with a descending gradient of 1 in 20 meets a flat section. Determine the length of the valley curve needed to ensure comfort at 70 km/h with SSD of 150 m under nighttime conditions.

   Hint

   Review both comfort rate and adequate sight distance calculations.

6. 6.

   Analyze the impact of an improperly designed valley curve that ignores minimum sight distance at night. What accidents might occur, and how can they be prevented?

   Hint

   Consider referencing visibility distances and headlight capabilities.