Imperial College London

Dr Ke Han

Faculty of EngineeringDepartment of Civil and Environmental Engineering

Senior Lecturer



+44 (0)20 7594 5682k.han Website CV




Mrs Maya Mistry +44 (0)20 7594 6100




605Skempton BuildingSouth Kensington Campus






BibTex format

author = {Han, K and Friesz, TL},
doi = {10.1007/s11067-017-9379-5},
journal = {Networks and Spatial Economics},
pages = {1095--1110},
title = {Continuity of the Effective Delay Operator for Networks Based on the Link Delay Model},
url = {},
volume = {17},
year = {2017}

RIS format (EndNote, RefMan)

AB - This paper is concerned with a dynamic traffic network performance model, known as dynamic network loading (DNL), that is frequently employed in the modeling and computation of analytical dynamic user equilibrium (DUE). As a key component of continuous-time DUE models, DNL aims at describing and predicting the spatial-temporal evolution of traffic flows on a network that is consistent with established route and departure time choices of travelers, by introducing appropriate dynamics to flow propagation, flow conservation, and travel delays. The DNL procedure gives rise to the path delay operator, which associates a vector of path flows (path departure rates) with the corresponding path travel costs. In this paper, we establish strong continuity of the path delay operator for networks whose arc flows are described by the link delay model (Friesz et al., Oper Res 41(1):80–91, 1993; Carey, Networks and Spatial Economics 1(3):349–375, 2001). Unlike the result established in Zhu and Marcotte (Transp Sci 34(4):402–414, 2000), our continuity proof is constructed without assuming a priori uniform boundedness of the path flows. Such a more general continuity result has a few important implications to the existence of simultaneous route-and-departure-time DUE without a priori boundedness of path flows, and to any numerical algorithm that allows convergence to be rigorously analyzed.
AU - Han,K
AU - Friesz,TL
DO - 10.1007/s11067-017-9379-5
EP - 1110
PY - 2017///
SN - 1566-113X
SP - 1095
TI - Continuity of the Effective Delay Operator for Networks Based on the Link Delay Model
T2 - Networks and Spatial Economics
UR -
UR -
VL - 17
ER -