  Technological advancements have brought increasing attention to Automated
Mobility on Demand (AMOD) as a promising solution that may improve future urban
mobility. During the last decade, extensive research has been conducted on the
design and evaluation of AMOD systems using simulation models. This paper adds
to this growing body of literature by investigating the network impacts of AMOD
through high-fidelity activity- and agent-based traffic simulation, including
detailed models of AMOD fleet operations. Through scenario simulations of the
entire island of Singapore, we explore network traffic dynamics by employing
the concept of the Macroscopic Fundamental Diagram (MFD). Taking into account
the spatial variability of density, we are able to capture the hysteresis
loops, which inevitably form in a network of this size. Model estimation
results at both the vehicle and passenger flow level are documented.
Environmental impacts including energy and emissions are also discussed.
Findings from the case study of Singapore suggest that the introduction of AMOD
may bring about significant impacts on network performance in terms of
increased VKT, additional travel delay and energy consumption, while reducing
vehicle emissions, with respect to the baseline. Despite the increase in
network congestion, production of passenger flows remains relatively unchanged.
