A novel network equilibrium model integrating urban aerial mobility

This paper explores the integration of urban aerial mobility (UAM) into the conventional transport network equilibrium problem, where travelers have the option to choose land-air amphibious vehicles for their daily commuting trips. The construction process of a land-air collaboration composite transportation network is first presented. Then, we further delve into the characterization of impedance function for various link types, using the classical queuing model that accounts for system capacity constraints. Subsequently, we develop a novel land-air collaboration network equilibrium (LAC-NE) model integrating the UAM concept, and it is translated into an equivalent mathematical programming problem, which admits solution existence and uniqueness. To efficiently address the model, based on the path-based gradient projection (GP) algorithm, an improved version with the path generation scheme is proposed. We conduct numerical experiments under diverse scenario settings to demonstrate the applicability of the LAC-NE model. These experiments examine the effects of UAM mode on network performance, revealing that the inclusion of land-air collaboration mode travelers would lead to distinct equilibrium states and network performance indicators. Furthermore, in comparison to the traditional network equilibrium model, the proposed model takes into account advanced low-altitude transportation (ALT), effectively alleviating urban traffic congestion. This paper offers valuable insights for the development of transportation policies aimed at addressing these emerging transportation mode challenges.