33.2.2. Relationship between Flow and Density

Try these first

1. 1.

   Define flow in the context of traffic.

   Hint

   Think about how traffic is measured.

2. 2.

   What is jam density?

   Hint

   Consider when traffic completely stops.

3. 3.

   What parameter represents the volume of vehicles passing a point in a time?

   • Density
   • Speed
   • Flow

   Hint

   Consider what traffic often counts.

4. 4.

   True or False: Jam density is when vehicles can still move.

   • True
   • False

   Hint

   Think of what congestion looks like.

5. 5.

   You observe that a freeway has a jam density of 400 vehicles/km and a free-flow speed of 80 km/h. What is the maximum flow on this freeway?

   Hint

   Use the maximum flow formula discussed in class.

6. 6.

   If the maximum flow of a highway is 6000 vehicles/hour and jam density is 300 vehicles/km, what is the free-flow speed?

   Hint

   Rearrange the maximum flow equation to solve for free-flow speed.