This paper explores the addressable market for Urban Air Mobility (UAM) as a multi-modal alternative in a community. To justify public investment, UAM must serve urban mobility by carrying a significant portion of urban traffic. We develop a traffic demand analysis method to estimate the maximum number of people that can benefit from UAM, for a given use case, in a metropolitan region. We apply our method to about three hundred thousand cross-bay commute trips in the San Francisco Bay Area. We estimate the commuter demand shift to UAM under two criteria of flexibility to travel time savings and three criteria of vertiport transfer times. Our results indicate that even for commuters with high value of time, and long transfer times at vertiports, almost forty-five percent of demand would benefit from UAM when the roads are highly congested. Even when the roads are mostly free, about three percent of the demand can benefit from UAM with the right combination of commuter flexibility and transfer times. Finally, our method also produces the number, location and distribution of demand over vertiports that can support value proposition, policy-making and technology research for UAM.

This article reviews the literature on urban air mobility (UAM), examining both the research challenges it presents and the transformative opportunities that make these challenges worth addressing. While UAM has historical precedents, the current iteration is born of novel aircraft technology, primarily electric vertical takeoff and landing (eVTOL) and electric short takeoff and landing (eSTOL) aircraft. These advances raise new questions in aerodynamics, control, and integration with urban infrastructure. We explore several key research areas, including aircraft design, vertiport development, network planning, and air traffic management. We also address the scalability challenges in air traffic management for high-density UAM operations and the potential of autonomous and remotely piloted systems. If new aircraft are to birth a new urbanism, they will do so by integrating aircraft engineering and computational intelligence in control, systems, robotics, and human factors.

View Video Presentation: https://doi.org/10.2514/6.2021-2338.vid Urban Air Mobility (UAM) has garnered billions of dollars in investment with early proofs-of-concept and deployments across the world. However, its viability as a transport mode will be strongly determined by benefits in travel time. Hence, before optimizing the planning and infrastructure provision for UAM’s deployment, the dynamics of UAM trips must first be simulated and understood in order to determine the total addressable market. This work contributes to the existing scholarship in several ways. First, we use an ultra-fast parallelized, GPU-based microsimulator, MANTA, to study the regional characteristics of UAM trips compared to driving trips, simulating millions of morning trips in the San Francisco Bay Area. Second, we provide a novel, data-driven approach to determine the demand of multi-modal UAM in different network designs, leveraging the speed of MANTA for iterative convergence. Third, we provide a granular yet regional-scale analysis of trips, showing congestion's sensitivity to the number of vertiports as well as transfer times. The number of benefited trips from UAM increases most significantly when the vertiport network expands from 10 to 30 vertiports, with lesser but steady growth beyond 30 vertiports. Assuming a transfer time of 2 minutes at each of the origin and destination vertiports, results indicate that the average distance of trips that benefit from multi-modal UAM decreases, ranging from approximately 54 km to 30 km, as the number of vertiports increases incrementally from 10 to 100. Travel times on the ground improve at all network designs, but the extent of benefit increases as the number of vertiports increases. Finally, we note that there is an equity component to UAM, in which travelers who do not opt to take UAM at all still benefit from the efficiency increases in the transportation network. This suggests that at particular network designs and deployments, UAM can be valuable to an entire metropolitan area.

Emerging unmanned aircraft systems (UAS) operations propose to introduce flights orders of magnitude higher than what the airspace handles today. What type of onboard control for enroute separation assurance increases productivity without compromising safety in the low-altitude airspace? This article quantifies the impact of two conflict detection and resolution approaches - pure speed control and pure direction control - on airspace productivity. We focus on small UAS traffic for goods movement in low altitude (under 400 feet) airspace. We compute three types of metrics, namely throughput, travel time extension and energy consumption, from simulations of unmanned traffic over a representative square area. As the inflow rates are increased, the corresponding outflow rates (throughput), travel time extensions and energy consumption for each type of control are measured. A representative power consumption model is developed for aircraft with both kinds of control. Without compromising safety, both direction control and speed control are equally good, unless the UAS are designed to be highly efficient while hovering. If the UAS have a hover power consumption that is equal to or less than one and a half times the minimum power consumption, speed control increases airspace productivity more than direction control.

Uncrewed aircraft systems are expected to revitalize traffic activities at under-utilized airports. These airports are often located in uncontrolled airspace and do not have an operating control tower to provide separation services for approaching aircraft. This presents unique challenges for the integration of uncrewed aircraft at non-towered airports. This paper offers a methodology to systematically assess traffic activities and quantify flight behaviors of crewed aircraft using historical flight data. To integrate uncrewed traffic in high-density traffic scenarios or during off-nominal flight situations, this paper assesses the concept of a holding stack above the traffic pattern airspace to handle increased traffic uncertainty and to provide safe integration procedures. Twelve non-towered airport environments, relevant for initial uncrewed cargo operations across Germany, California, and Texas, are investigated to assess concept feasibility and real-world implementation. Based on the interaction of various quantitative measures, results are presented on the feasibility of holding stacks in the terminal airspace and the influence of crewed aircraft’s historical flight behavior on different integration procedures for uncrewed aircraft. The analysis of various measures suggests that six airports are comparatively suitable candidates for holding layers above the airport traffic pattern, with holding altitudes to start between 2500 and 3500 feet above the ground.