Deciding when to establish a new highway maintenance office and where to put this new office is often a difficult process. A modeling technique may assist in making such difficult decisions. The p-median model is widely used in the business field to study the attractiveness between potential service facilities and the audience receiving these services. The model has proved successful in selecting optimum locations for business and government facilities, and it may be readily adapted to the highway field office problem. The theoreticalbasis, characteristics, and constraints associated with the p-median model are discussed. For any fixed number of service facilities, the model finds their optimum locations, such that total system travel is minimized between the facilities and the maintenance sites (adjacent nodes in the road network). The model can also be adapted to optimize two levels of maintenance offices, in which groups of offices at the lower level report to offices at an upper level. Several examples are used to show modeling methods for selecting the best number of field offices and their optimum locations. Weighting factors (lane-miles of pavement, population, maintenance budgets, etc.) Are applied to travel distances to modify the attractiveness between nodes and facilities and thus improve the model. An example is given to illustrate calibrating the model in this manner. This paper appears in transportation research record no. 1268, Highway maintenance operations and research 1990.
Samenvatting