Spatial interactions usually include a variety of movements such as:
- travel,
- migration,
- transmission of information,
- journeys to work or shopping,
- retailing activities, or
- freight distribution.
The basis of spatial interaction is based on three phenomena:
- complementarity (a deficit of a good or product in one place and a surplus in another),
- transferability (possibility of transport of the good or product at a cost that the market will bear), and
- lack of intervening opportunities (where a similar good or product that is not available at a closer distance).
