33.2. Greenshield’s Macroscopic Stream Model

Try these first

1. 1.

   What is the relationship defined by Greenshield's model?

   Hint

   Think about how speed changes as more cars are on the road.

2. 2.

   What does 'free flow speed' represent in the model?

   Hint

   Consider a clear road without any delays.

3. 3.

   What kind of relationship does Greenshield’s model assume between speed and density?

   • Exponential
   • Linear
   • Quadratic

   Hint

   Think about how cars behave on a roadway as they come closer together.

4. 4.

   True or False: The speed in Greenshield's model rises as density increases.

   • True
   • False

   Hint

   Recall the relationship presented in this context.

5. 5.

   Given a traffic situation with a jam density of 300 vehicles/km and a free flow speed of 90 km/h, derive the equations for flow and determine maximum flow.

   Hint

   Utilize both maximum flow principles and Greenshield's equations.

6. 6.

   Calculate the speed when the density is 60 vehicles/km and the jam density remains constant at 240 vehicles/km.

   Hint

   Insert values in the correct formula presented in your readings.