Location of multiple server common service centers or public facilities for minimizing general congestion and travel cost functions

We propose a model and solution methods, for locating a fixed number of multiple-server, congestible common service centers or congestible public facilities. Locations are chosen so to minimize consumers’ congestion (or queuing) and travel costs, considering that all the demand must be served. Customers choose the facilities to which they travel in order to receive service at minimum travel and congestion cost. As a proxy for this criterion, total travel and waiting costs are minimized. The travel cost is a general function of the origin and destination of the demand, while the congestion cost is a general function of the number of customers in queue at the facilities.