UC Davis

The imbalance between increasing travel demand by passengers and the stagnant growth of transportation infrastructure capacity, particularly in urban areas, has caused dramatic impacts on traffic congestion, the environment, public health, and energy efficiency. Consequently, the development of sustainable and resilient transportation systems has become an increasingly challenging task. Travel demand management (TDM) is a set of strategies aimed at redistributing travel demand in time or space to alleviate the imbalance between travel demand and available infrastructure capacities. Active transportation (AT), which includes walking and cycling, has emerged as a popular TDM approach in modern urban areas, with the potential to reduce vehicular travel (VT) demand and alleviate traffic congestion. However, potential barriers such as longer commuting times and adverse health effects, including exposure to hazardous air pollution and traffic injuries, often dissuade travelers from choosing AT. Therefore, understanding the complex relationship between AT and VT demand is crucial, especially when considering the health effects associated with these modes of transportation, such as the negative impact of air pollution and the benefits of physical activity.

Nevertheless, it is important to acknowledge that modeling active transportation in urban areas without considering the influence of Transportation Network Companies (TNCs), particularly the effects of enhancing vehicle occupancy through e-pooling and express pool services, can lead to biased findings. Hence, in this study, I model the AT and VT traveling modes in a multi-modal network problem taking into account TNC services, such as, e-hailing, e-pooling, and express pool. The objective is to analyze passengers' choices among active transportation, solo driving, and TNC services, considering various trade-offs related to health, monetary, time, and inconvenience costs, and their subsequent impacts on traffic network performance. Given the non-separable and asymmetric nature of the disutility functions associated with multi-modal travel modes, the problem is formulated as a mixed complementarity problem. Accordingly, the discussion the existence and uniqueness of solution(s) are conducted based on the properties of equilibrium models in my dissertation.

By utilizing the proposed mathematical model, the study aims to assess the market share of active transportation, solo driving, and TNC modes at the equilibrium state, providing valuable insights for policymakers seeking to enhance mobility, energy efficiency, public health, and environmental outcomes. These components are integral to the establishment of a sustainable transportation system.