Travel Behavior

Zero-emission vehicle exposure within U.S. carsharing fleets and impacts on sentiment toward electric-drive vehicles

Shaheen, Susan
Martin, Elliot
Totte, Hannah
2020

Reducing carbon emissions from the United States (U.S.) transportation sector has emerged as a priority action to combat climate change. Carsharing and zero-emission vehicles (ZEVs) could be integral to creating a more sustainable transportation system. This paper presents the results of a study that evaluated the impacts of ZEV exposure on U.S. carsharing users. Surveys were administered to control and experimental groups of carsharing members that used shared PHEVs or EVs. Results showed that users who drove shared PHEVs or EVs more frequently were more likely to exhibit improved ZEV...

Ridesharing in North America: Past, Present, and Future

Chan, Nelson D.
Shaheen, Susan A.
2011

Since the late-1990s, numerous ridematching programs have integrated the Internet, mobile phones, and social networking into their services. Online ridematching systems are employing a range of new strategies to create “critical mass:” 1) regional and large employer partnerships, 2) financial incentives, 3) social networking to younger populations, and 4) real-time ridematching services that employ “smartphones” and automated ridematching software. Enhanced casual carpooling approaches, which focus on “meeting places,” are also being explored. Today, ridesharing represents approximately 8...

California's Zero-Emission Vehicle Mandate: Linking Clean-Fuel Cars, Carsharing, and Station Car Strategies

Shaheen, Susan
Wright, John
Sperling, Daniel
2002

To reduce transportation emissions and energy consumption, policymakers typically employ one of two approaches—changing technology or changing behavior. These strategies include demand management tools, such as ridesharing and vehicle control technologies—cleaner fuels and fuel economy. Despite the benefits of a combined policy approach, these strategies are normally employed separately. Nevertheless, they have been linked occasionally, for instance in theelectric station car programs of the 1990s. Station cars are vehicles used by transit riders at the start or end of a trip.In 1990, the...

An Initial Assessment of the Potential Weather Barriers of Urban Air Mobility

Reiche, Colleen PhD
Cohen, Adam
Fernando, Chris
2021

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...

Going My Way? Understanding Curb Management and Incentive Policies to Increase Pooling Service Use and Public Transit Linkages in the San Francisco Bay Area

Darling, Wesley
Broader, Jacquelyn
Cohen, Adam
Shaheen, Susan, PhD
2023

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...

Willingness of Hurricane Irma Evacuees to Share Resources: A Multi-Modeling Approach

Wong, Steven D.
Yu, Mengqiao
Kuncheria, Anu
Shaheen, Susan A.
Walker, Joan L.
2022

Recent technological improvements have greatly expanded the sharing economy (e.g., Airbnb, Lyft, and Uber), coinciding with growing need for transportation and sheltering resources in evacuations. To understand influencers on sharing willingness in evacuations, we employed a multi-modeling approach across four sharing scenarios using three model types: 1) four binary logit models that capture each scenario separately; 2) a multi-choice latent class choice model (LCCM) that jointly estimates multiple scenarios via latent classes; and 3) a portfolio choice model (PCM) that estimates...

The Impact of Carsharing on Public Transit and Non-Motorized Travel: An Exploration of North American Carsharing Survey Data

Martin, Elliot
Shaheen, Susan
2011

By July 2011, North American carsharing had grown to an industry of nearly 640,000 members since its inception on the continent more than 15 years ago. Carsharing engenders changes in member travel patterns both towards and away from public transit and non-motorized modes. This study, which builds on the work of two previous studies, evaluates this shift in travel based on a 6281 respondent survey completed in late-2008 by members of major North American carsharing organizations. Across the entire sample, theresults showed an overall decline in public transit use that was statistically...

What’s the ‘Big’ Deal with Shared Micromobility? Evolution, Curb Policy, and Potential Developments in North America

Shaheen, Susan
Cohen, Adam
Broader, Jacquelyn
2021

Shared micromobility – or short-term access to shared bikes and scooters – provides a flexible alternative for households living in urban areas, individuals seeking first- and last-mile connections to public transportation, and those without access to a private vehicle trying to reach jobs and essential services. In this paper, the authors discuss the history, growth, and evolution of bike and scooter sharing in North America; summarize the demographics and impacts of shared micromobility; and explore shared micromobility policies and practices for managing devices and operations such as:...

Bikesharing in Europe, the Americas, and Asia: Past, Present and Future

Shaheen, Susan A.
Guzman, Stacey
Zhang, Hua
2010

Growing concerns over global motorization and climate change have led to increasing interest in sustainable transportation alternatives, such as bikesharing (the shared use of a bicycle fleet). Since 1965, bikesharing has grown across the globe on four continents including: Europe, North America, South America, and Asia (including Australia). Today, there are approximately 100 bikesharing programs operating in an estimated 125 cities around the world with over 139,300 bicycles. Bikesharing’s evolution is categorized into three generations: 1) White Bikes (or Free Bike Systems); 2) Coin-...

Carsharing and the Built Environment: Geographic- Information System-Based Study of One U.S Operator

Stillwater, Tai
Mokhtarian, Patricia L.
Shaheen, Susan A.
2009

The use of carsharing vehicles over a period of 16 months in 2006-07 was compared to built environment and demographic factors in this GIS-based multivariate regression study of an urban U.S. carsharing operator. Carsharing is a relatively new transportation industry in which companies provide members with short-term vehicle access from distributed neighborhood locations. The number of registered carsharing members in North America has doubled every year or two to a current level of approximately 320,000. Researchers have long supposed that public transit access is a key factor driving...