18.2.2. Length of the valley curve

Try these first

1. 1.

   What is a valley curve?

   Hint

   Think about the shape of a valley.

2. 2.

   What does SSD stand for in road design?

   Hint

   What do you need to safely stop your vehicle?

3. 3.

   What does a valley curve help achieve in road design?

   • Increase gradient
   • Ensure smooth transitions
   • Reduce visbility

   Hint

   Think about the driving experience on curves.

4. 4.

   True or False: Comfort criteria focus solely on the length of the curve.

   • True
   • False

   Hint

   Remember the factors involved in comfort.

5. 5.

   You have a valley curve with descending gradient n = 1 in 20 and ascending n = 1 in 35. For a design speed of 100 km/h, calculate L considering both comfort and safety criteria.

   Hint

   Do not forget to evaluate both cases; which conditions govern your final answer?

6. 6.

   Given a scenario where poor visibility conditions lead to frequent accidents at night, analyze how you would redesign the valley curve with a focus on safety.

   Hint

   How does sight distance adapt to curve length?