Abstract
This study addresses itself to the location-allocation problem within a framework of spatial interaction model. The study has found that the spatial interaction model may be interpreted as a solution to a linear programming problem which minimizes the allowable level of supply at each demand point. It may be also interpreted as a solution to its dual problem which maximizes the total amount of demand subject to the current level of demand at each supply point. Assuming potential demand is known and stable, we can use the duality to find the optimum allocation of supply which realizes the planned supply level with minimum of resources. It is also possible to use duality to find the minimum travel distance allocation of supply which realizes the planned supply level.
