Urban transportation demand increases with the growing number of socio-economic activities, which derives a variety of traffic problems. There are two main objectives: to ensure a proper development of a city’s transportation services and to reduce externalities caused by private transport modes. Emphasizing the use of transit-oriented development (TOD) in urban transport planning strategies is necessary to achieve the objectives. In transportation management, when planners tend to design TOD, the first step is to determine the potential needs for transit. However, there is an insufficient amount of research based on estimating the need for TOD. We propose a traffic planning model to assess the transport performance of a TOD city. The proposed model tests modal split and route choice simultaneously, which explains the seamless issue of the first mile and last mile derived by transit, and the interaction of multiple vehicle classes in the network at the same time. We develop an algorithm which combined diagonalization method and gradient projection method to solve this proposed model. This research report includes numerical examples for model validation purposes. Finally, we expect the computational results justify that the model and algorithm we proposed can evaluate the TOD traffic assignment problem completely and also provide the guidance to the TOD assessment.