Public Transp (2009) 1: 233–251 DOI 10.1007/s12469-009-0015-8 ORIGINAL PAPER Congested multimodal transit network design Quentin K. Wan · Hong K. Lo Published online: 5 November 2009 © Springer-Verlag 2009 Abstract The planning of transit services is vital to transit-oriented metropolises. It is a complex, multi-objective decision process, especially for services operated by the private sector. Traveler’s desire for direct, affordable, and quality services often con- flicts with the profit-making objective of private operators. In a multi-modal network, partly collaborative and partly competitive interactions among transit modes further complicate the problem. To simplify the planning problem, existing studies gener- ally consider transit network design from the perspective of a single mode while ne- glecting the modal interactions. The lack of a comprehensive approach across transit modes may result in an unbalanced supply of transit services, weakening the financial viability of the services and, more importantly, adding unnecessarily to congestion, especially in already congested districts. This study explicitly considers these inter- actions in a multi-modal network framework. We develop a systematic phase-wise methodology for multi-modal network design, considering both the effect of con- gestion and integration of modal transfers. Inter-route and inter-modal transfers are modeled through the State Augmented Multi-modal (SAM) network approach devel- oped in earlier studies. An illustrative example is included to demonstrate the design procedure and its salient features. 1 Introduction Transit systems play an important role in the planning and development of transit- oriented metropolises, as in many Asian and European cities. Transit network design Q.K. Wan Transport Research Institute, Napier University, Edinburgh, UK H.K. Lo ( ) Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong, China e-mail: cehklo@ust.hk