Shared mobility (SM) and active transportation (AT) (i.e., walking and cycling) are common transportation demand management options in modern cities. While SM and AT both potentially reduce vehicle demands, the complex trade-offs between SM and AT are usually ignored. Depending on SM’s flexibility and affordability, it may attract AT commuters, causing an increase in the vehicular traffic flow. As AT commuters’ exposures to air pollution and traffic injuries grow when traffic flows increase, they may become even more likely to switch to SM. However, higher traffic flows may worsen vehicular traffic performance and incentivize SM users to shift to AT. This dissertation proposes to model AT and SM as separate or joint travel modes in a multi-modal network equilibrium problem and study passengers’ choices of AT and/or SM to examine the complex trade-offs of players regarding monetary, time, inconvenience, and health costs, and the consequent impacts on traffic network performance. The proposed mathematical model could be used to examine the market share of various transportation modes at the equilibrium(a) status, offering insights to policymakers who aim to enhance mobility, energy, public health, and environmental outcomes, all critical components of a sustainable transportation system.
