Thisarticleisconcernedwiththecontinuousnetworkdesignproblemontrafficnetworks,assumingsystemoptimumtrafficflowconditionsandtime-dependentdemand.Alinearprogrammingformulationisintroducedbasedonadynamictrafficassignment(DTA)modelthatpropagatestrafficaccordingtothecelltransmissionmodel.Theintroducedapproach