Transit services play a more important role in the era of sustainable transportation systems. Previous studies on transit services were limited because they were often treated as an auxiliary mode to private car transportation, with limited ability to model the problems and phenomena that are important and unique in the transit system. With the recent advancement of state-of-the-art transit assignment tools, they open up new ways and methodologies to consider important but challenging issues in modeling the transit system. In this study, we developed salient approaches for transit assignment and demand modeling, based on which we can better model the responses of the entire transit system and travelers to any changes in the transit services. This enables us to better understand the inte...[ Read more ]

Transit services play a more important role in the era of sustainable transportation systems. Previous studies on transit services were limited because they were often treated as an auxiliary mode to private car transportation, with limited ability to model the problems and phenomena that are important and unique in the transit system. With the recent advancement of state-of-the-art transit assignment tools, they open up new ways and methodologies to consider important but challenging issues in modeling the transit system. In this study, we developed salient approaches for transit assignment and demand modeling, based on which we can better model the responses of the entire transit system and travelers to any changes in the transit services. This enables us to better understand the interactions in a transit system, which is imperative for transit services planning.

On the demand estimation for transit services, forecast of ridership plays a crucial role in service planning. Contrary to the traditional wisdom, our survey found that many of the service attributes, such as fare, are not accurately known to travelers and common practices lead to biased demand estimation. This study depicted survey results to illustrate the possible biases involved, and developed approaches to better address the effects of these biases. The result leads to more accurately calibrated utility functions and hence better demand forecasting models that are more representative of travelers’ actual choice behavior.

On transit services planning, we acknowledge the common practices of multiple-leg transit trip and inter-route transfers. We developed a planning tool that explicitly considers transfers in a multimodal network, which is then incorporated into the design procedure developed in this study for transit network design under congestion. Based on this framework, we illustrate, via with two management strategies for transit services, how a transit system can be better managed to achieve cost-effectiveness.