INFORMS PITTSBURGH — 2006 199 4 - A Cluster - Lightening Route Reduction Strategy for the Vehicle Routing Problem with Time Windows

not available at this time 3 An Inner Approximation Algorithm for the Discrete Time Varying User Equilibrium Problem Athanasios Ziliaskopoulos, Department of Mechanical and Industrial Engineering, University of Thessaly, Volos, 38334, Greece, [email protected] Traffic assignment models usually assume a convex relationship of link travel time with flow. This paper argues that this is contradictory to what is observed on actual street networks, where the same flow conditions can be observed under at least two states of traffic: a congested state with high link travel time and an un-congested one with lower travel time. A 2-link example network is solved using a Greenshields type density based link performance function and is used to explain elementary concepts. Finally, some thoughts on potential formulations are discussed that are consistent with traffic flow models without, however, making an effort to propose a tractable one.