8.3.3. Doubly constrained growth factor model

Try these first

1. 1.

   What is the primary purpose of the doubly constrained growth factor model?

   Hint

   Think about why we need to manage trips coming from and going to different locations.

2. 2.

   Define what is meant by 'balancing factor'.

   Hint

   Consider how we might need to correct our data to fit actual numbers.

3. 3.

   What does the doubly constrained growth factor model rely on?

   • One growth factor
   • Two growth factors
   • Three growth factors

   Hint

   Recall the necessity of both origins and destinations.

4. 4.

   True or False: The doubly constrained model is less accurate than the singly constrained model.

   • True
   • False

   Hint

   Consider the factors applying in both models.

5. 5.

   Given productions of 150 trips and attractions of 150 trips for three zones, calculate the balancing factors and determine the trips in a trip matrix using the doubly constrained model.

   Hint

   Start from setting b to 1, and remember to frequently update the trip totals based on calculated factors.

6. 6.

   Analyze a scenario where only one constraint (trip production) is known. Discuss the effects on trip distribution and the model’s accuracy.

   Hint

   Consider the implications of having incomplete data on modeling and trips.