11.2.1. Design speed

Try these first

1. 1.

   What is design speed?

   Hint

   Think about the conditions under which speed is considered safe.

2. 2.

   How does design speed differ from legal speed limit?

   Hint

   Consider the focus of each definition.

3. 3.

   What is design speed?

   • A legal speed limit
   • The highest speed for safe travel under ideal conditions
   • The speed favored by drivers

   Hint

   Focus on speed in ideal conditions.

4. 4.

   True or False: Design speed and legal speed limit are the same.

   • True
   • False

   Hint

   Consider their definitions.

5. 5.

   If a highway has a design speed of 90 km/h, what geometric design features would you expect to see, and why are they necessary?

   Hint

   Consider what happens at higher speeds with visibility.

6. 6.

   How might a city planner justify setting a lower design speed of 40 km/h in a congested area?

   Hint

   Think about urban dynamics and safety.