4.7. Summary

Try these first

1. 1.

   What does PIEV stand for?

   Hint

   Think about the stages of a driver's reaction.

2. 2.

   Why is the 85th percentile important in transportation design?

   Hint

   Consider how this impacts design standards.

3. 3.

   What does the 85th percentile measure?

   • Average reaction time
   • Performance level that 85% can meet
   • Maximum speed limit

   Hint

   Relate it to safety design.

4. 4.

   True or False: Vision and reaction time are unrelated factors in traffic safety.

   • True
   • False

   Hint

   Consider how drivers perceive their environment.

5. 5.

   Design a transportation system for a city focused on pedestrian safety. What human, vehicle, and roadway factors must be considered?

   Hint

   Think about how to protect vulnerable users.

6. 6.

   Evaluate an existing traffic accident case. Identify how neglecting the PIEV stages might have contributed.

   Hint

   Look for a breakdown in the steps from perception to action.