With the rapid growth of automobile transport over the last century, conflicts between automobile and pedestrian transport have been viewed as a major concern in urban and transport planning. Elevated and underground pedestrian networks, which compensate for sidewalks at the street level and provide alternative options for pedestrians, have been developed in many cities. Elevated and underground pedestrian networks offer pedestrian–car separation in a vertical dimension and efficient connections between transit services and cities for subway passengers. This study aims to provide a balanced understanding of the development of underground pedestrian networks and propose supportive strategies for decision makers, planners, and designers concerned with the future implementation of underground pedestrian networks and the building of three-dimensional pedestrian networks in cities. The study applied textual analysis to examine the topic. The study indicated that three-dimensional pedestrian systems were developed based on historical precedents. It highlighted important considerations (such as dense cities, disaster mitigation and protection, and urban functions) in developing underground pedestrian networks in cities. Furthermore, it discussed significant aspects in planning and designing such networks, including safety, ease of orientation, and convenience. The paper also discussed policy implications in developing underground pedestrian networks and the building of three-dimensional pedestrian networks in cities.