Title: On the master route problem Abstract: Assume that a company has a set of customers to which it delivers products on a regular basis. Each day, however, the list of customers to be served is only a proper subset of the set of all customers. The company would like to design a master route to serve all customers. A route is called a master route, if (i) it is an optimal route, and (ii) the ordering of customers remains optimal even after deleting any subset of the customers. Some time ago we gave a complete characterization of cases when the problem can be solved efficiently. In our talk we discuss the structure of networks for which the master route problem can be solved efficiently.