### QoS-aware Multicommodity Flows and Transportation Planning

George Tsaggouris & Christos Zaroliagis
We consider the emph{QoS-aware Multicommodity Flow} problem, a natural generalization of the weighted multicommodity flow problem where the demands and commodity values are elastic to the Quality-of-Service characteristics of the underlying network. The problem is fundamental in transportation planning and also has important applications beyond the transportation domain. We provide a FPTAS for the QoS-aware Multicommodity Flow problem by building upon a Lagrangian relaxation method and a recent FPTAS for the non-additive shortest path problem.