Doubly constrained Gravity ModelTrip Distribution

FAQs

• When to use doubly constrained model?

  The doubly constrained model can be used when the following condition is satisfied.

  When sum of all the trips attracted to all the attraction zones will be equal to the total number of trips produced in a production zone. Mathematically: $$\nonumber \sum \limits_{j} T_{ij} = O_{i}$$
  When sum of trips produced for all the trip production zones will be equal to the number of trips attracted to a destination zone. Mathematically: $$\nonumber \sum \limits_{j} T_{ij} = D_{i}$$