Adam Cohen

Advanced Air Mobility (AAM) includes innovative aviation technologies and services that could alter how people and goods are transported. However, future AAM growth and potential regional integration are uncertain and influenced by a range of factors. In this paper, we report findings from expert interviews (n = 35) and a scenario planning workshop (n = 32 stakeholders), conducted between August 2024 and July 2025, to explore potential alternative futures for AAM at the San Francisco International Airport (SFO) and the greater San Francisco Bay Area. We applied a two-axis framework: regulatory environment (supportive vs. restrictive) and economic conditions (vibrant vs. stagnant). Building on this, we developed four plausible scenarios for the 2025 to 2030 and post-2030 time horizons. We apply the SPELT (social, political, economic, legal, technological) framework to assess cross-cutting drivers, tensions, and indicators across the four scenarios based on two timeframes, i.e., 2025 to 2030 and post-2030. Our analysis of the scenarios reveals that regulatory clarity and macroeconomic conditions are key influencers that define the pace and scale of AAM growth, while community impacts (e.g., noise), public acceptance, and infrastructure availability are constraints. These factors largely determine whether technical readiness can translate into scaled deployment. Cross-cutting themes across all of the scenarios consistently shape the outcomes: (1) equity and community acceptance strongly influence political feasibility; (2) SFO and other airports can serve dual roles as conveners and practical enablers but face risks of stranded assets; and (3) flexible, modular infrastructure and incremental investment strategies reduce uncertainty for SFO and other Bay Area airports and public agencies. Together, the findings suggest that while the future of AAM is uncertain, policy and planning responses can assist airports, local governments, and other public agencies in preparing for potential developments.

Bike lending offers a service that enables individuals to borrow bicycles for short-term use (i.e., ranging from 2 hours to 36 months), typically from designated locations within cities, campuses, or communities. Unlike bikesharing systems that typically rely on automated kiosks and/or undocked and free-floating devices for public access, bike lending involves a managed program with staff, similar to a library model. These programs can be administered by community organizations, bike shops, public libraries, and other local entities. They are typically community- or membership-based, with many programs associated with non-profit organizations or publicly owned and operated. In this paper, we investigate bike lending in the United States and Canada as of Spring 2024, including a literature review, the identification and characterization of bike lending programs (n = 55), expert interviews (n = 24), a survey of bike lending operators (n = 31), and 2 focus groups with a total of 12 participants. Insights from expert interviews and operator surveys highlight the experiences of professionals involved in bike lending. The focus groups capture the experiences of bike lending users. This paper finds that North American bike lending is often tailored to the specific needs of communities, such as youth, low-income individuals, and the general population. More sustained funding could support program expansion and diversify bike offerings. Enhancing cycling infrastructure, such as adding dedicated bike lanes and paths, could improve overall cycling safety and increase participation in bike lending programs. This study’s findings could help strengthen existing bike lending programs, guide the development of new initiatives and supportive policies, and enhance safe bicycle use for participants.

Despite lower user costs, only 20% to 40% of transportation network company (TNC) users select a pooled, or shared, ride option. Why are existing TNC users not selecting the pooled option or using TNCs to connect to public transit, and what role do built environment features and incentives play in their decision? This study explores the factors that influence TNC user decisions through a multi-method approach comprising photovoice small group discussions and a workshop. Between March 2021 and May 2021, 15 San Francisco Bay Area TNC users shared photographs they took of TNC pick-up locations through two-to-three-person guided small group discussions. The photos revealed that users prefer waiting in retail or in well-lit, good-visibility locations. Participants’ primary concern was personal safety, particularly female users who may take additional precautions when walking to pick-up locations and waiting for and taking rides. In July 2021, 12 photovoice participants and 5 stakeholders provided feedback on key findings from the photography discussions. The pooling improvement strategies identified include the following: designated TNC stops with lighting and marked pick-up areas; enhanced in-app safety features; TNC partnerships with employers and retailers to incentivize riders; and mode transfer discounts for connecting TNCs to public transit. The findings suggest that safety related to the built environment plays an outsized role in a TNC user’s decision to pool or connect to public transit, and the out-of-vehicle portion of the TNC trip should be equally considered when developing policies to increase pooling.

In recent years, innovative mobility and shifts in travel and consumption behavior are changing how people access and use the curb. Shared mobility—the shared use of a vehicle, bicycle, scooter, or other mode—coupled with outdoor dining, curbside pick-up, and robotic delivery are creating new needs related to the planning, management, and enforcement of curb access. This study examines curb planning and management from several angles, such as safety, social equity, and multimodal connections. This research employs a multi-method approach to identify the changing needs for curb space management and how to meet these needs through new planning and implementation policies and strategies. As part of this study, the authors conducted 23 interviews. Respondents were chosen to represent public, private, and non-profit sector perspectives. Additionally, the authors employed a survey of 1,033 curb users and 241 taxi, transportation network company (TNC), and public transportation drivers. The study finds that changes in mode choice and curbside use can result in a variety of impacts on access, social equity, congestion, device management, pick-up and drop-off, and goods delivery, to name a few. The curb also has the potential to be disrupted by emerging modes, such as robotic delivery vehicles (also known as personal delivery devices) and automated vehicles. As these emerging developments continue to impact the curb, it is becoming increasingly important for policymakers to have an appropriate framework for planning and managing curb space in urban areas.

Advanced air mobility (AAM) is a broad concept enabling consumers access to on-demand air mobility, cargo and package delivery, healthcare applications, and emergency services through an integrated and connected multimodal transportation network. While a number of technical and social concerns have been raised about AAM, early use cases for emergency response and aeromedical transport may be key to demonstrating the concept and building public acceptance. Using a five-step multi-method approach consisting of preliminary scoping, modeling performance metrics, developing baseline assumptions, analyzing scenarios, and applying a Monte Carlo sensitivity analysis, this study examines the potential operational and market viability of the air ambulance market using a variety of aircraft and propulsion types. The analysis concludes that electric vertical take-off and land (eVTOL) aircraft could confront a number of operational and economic challenges for aeromedical applications compared to hybrid vertical take-off and land (VTOL) aircraft and rotorcraft. The study finds that technological improvements such as reduced charge times, increased operational range, and battery swapping could make the eVTOL aircraft more reliable and cost-effective for aeromedical transport.

Advanced air mobility (AAM) is a broad concept enabling consumers access to on-demand air mobility, cargo and package delivery, healthcare applications, and emergency services through an integrated and connected multimodal transportation network. However, a number of challenges could impact AAM’s growth potential, such as autonomous flight, the availability of take-off and landing infrastructure (i.e., vertiports), integration into airspace and other modes of transportation, and competition with shared automated vehicles. This article discusses the results of a demand analysis examining the market potential of two potential AAM passenger markets—airport shuttles and air taxis. The airport shuttle market envisions AAM passenger service to, from, or between airports along fixed routes. The air taxi market envisions a more mature and scaled service that provides on-demand point-to-point passenger services throughout urban areas. Using a multi-method approach consisting of AAM travel demand modeling, Monte Carlo simulations, and constraint analysis, this study estimates that the air taxi and airport shuttle markets could capture a 0.5% mode share. The analysis concludes that AAM could replace non-discretionary trips greater than 45 min; however, demand for discretionary trips would be limited by consumer willingness to pay. This study concludes that AAM passenger services could have a daily demand of 82,000 passengers served by approximately 4000 four- to five-seat aircraft in the U.S., under the most conservative scenario, representing an annual market valuation of 2.5 billion USD.

Since the early 20 ^th century, inventors have conceptualized “plane cars” and other urban aerial transportation. Emerging innovations in electrification, automation, and other technologies are enabling new opportunities for on-demand air mobility, business models, and aircraft design. Urban air mobility (UAM) envisions a safe, sustainable, affordable, and accessible air transportation system for passenger mobility, goods delivery, and emergency services within or traversing metropolitan areas. This research employed a multi-method approach comprised of 106 interviews with thought leaders and two stakeholder workshops to construct the history, ecosystem, state of the industry, and potential evolution of UAM. The history, current developments, and anticipated milestones of UAM can be classified into six phases: 1) “flying car” concepts from the early 1910s to 1950s, 2) early UAM operations using scheduled helicopter services from the 1950s to 1980s, 3) re-emergence of on-demand services starting in the 2010s, 4) corridor services using vertical take-off and landing (VTOL) envisioned for the 2020s, 5) hub and spoke services, and 6) point-to-point services. In the future, UAM could face several barriers to growth and mainstreaming, such as the existing regulatory environment; community acceptance; and concerns about safety, noise, social equity, and environmental impacts. UAM also could be limited by infrastructure and airspace management needs, as well as business model constraints. The paper concludes with recommendations for future research on sustainability, social and economic impacts, airspace integration, and other topics.

Urban Air Mobility (UAM), a subset of advanced air mobility, is a concept that envisions safe, sustainable, affordable, and accessible air transportation for passenger mobility, cargo delivery, and emergency management within or traversing a metropolitan area. In recent years, several companies have designed and tested enabling elements of this concept, including; prototypes of vertical take-off and landing (VTOL) aircraft, operational concepts, and market studies to understand potential business models. While UAM may be enabled by the convergence of several factors, a number of barriers such as weather could present challenges to scaling operations. This research discusses the potential weather and public acceptance challenges for operations in adverse conditions. This article presents a comprehensive seasonal and diurnal climatology analysis using historical observations across anticipated operational altitudes (surface- 5000 ft AGL) at ten metropolitan areas across the United States for the NASA Aeronautics Research Mission Directorate (ARMD). Public perceptions of weather-related societal barriers were evaluated through a five-city general population survey (n = 1,702) where respondents were asked about their views regarding flying in a small aircraft in a variety of adverse weather conditions using a six statement 5-point Likert scale. The results of the climatology analysis found weather most favorable in Los Angeles and San Francisco, with much less favorable conditions in Denver, New York City, and Washington D.C. In the future, equipping automated vehicles, unmanned aircraft systems, and VTOLs with meteorological sensors coupled with machine learning and artificial intelligence could enhance predictive capabilities that reduce flight cancellations and delays for travelers.

This report presents the findings from an evaluation of the September 2018 Viva CalleSJ open streets event in San José,CA. The research was designed to assess the success of the event, guide planning for future open streets events, and inform potential funders and community partners about the benefits of such events. To gather the impressions of participants, local residents, and workers at businesses along the event route, the mixed-methods study analyzed results from a survey of 1,571participants, 114 interviews with community members and businesses, and participant observations. Researchers also examined social media presence and a related augmented reality gaming component. The study found that Viva CalleSJ 2018 participants were resoundingly positive about their experience. Many said that the event brought people together from across the city and inspired a sense of community and civic pride, and the majority of participants benefited from at least one hour of physical activity. Most local businesses and residents viewed the event positively as well, and many food and beverage outlets appeared to benefit from increased patronage during the event. However, some shop keepers along the event route and residents in surrounding neighborhoods were not aware of Viva CalleSJ in the weeks prior to it happening or did not have a clear understanding of how it might impact them. Some were wary of the road closures and in some cases were ultimately frustrated by what they perceived to be negative impacts on their businesses.