Network Equilibrium Models with Combined Modes

Many trips in urban areas are taken by using more than one mode, such as the so called “kiss'n ride” or “park'n ride” trips; the first part of the trip is taken by the private care and then completed by taking one or more transit modes. We present in this paper several approaches to formulating network equilibrium models with combined modes. One of these approaches results in a new network equilibrium model, where the combined mode is considered as a distinct alternative in a demand model, and the network flows are suitably modelled on different modal subnetworks. The mathematical structure of the model is analysed and solution algorithms are outlined.