Environment

Zero-Emission Bus Implementation Guidebook for California Transit Fleets

Lipman, Timothy, PhD
Rogers, Emily, MS
2023

Transit bus operations in California are experiencing new challenges due to economic conditions and the ongoing global pandemic. A confluence of factors has created a focus on this critical public-needs serving industry, due to state and local efforts to reduce emissions of pollutants and climate-changing gases. Transit bus operations in California provide essential and additional useful services that offer critical mobility to needy populations (elderly and handicapped) as well as many other groups for whom transit buses provide the most economical, convenient, and low-emission options....

Exploring the Future of Integrated Transportation Systems in the United States from 2030 to 2050: Application of a Scenario Planning Tool

Shaheen, Susan, PhD
Camel, Madonna
Lee, Kunik
2013

Intelligent transportation systems (ITS) have primarily focused on systems management. To further improve connectivity and safety in the future, ITS might embrace a more holistic planning approach. While the future of ITS remains an open question, its evolution is closely linked to how the world evolves on many dimensions, social, political, economic, legal, and environmental. In this paper, the authors present results from four expert workshops. These consisted of an initial steering committee workshop (February 2011), two expert scenario-planning workshops (June 2011), and a final...

Shared-Use Vehicle Systems

Shaheen, Susan
2002

In recent years, shared-use vehicle systems have garnered a great deal of interest and activity internationally as an innovative mobility solution. In general, shared-use vehicle systems consist of a fleet of vehicles that are used by several different individuals throughout the day. Shared-use vehicles off the convenience of the private automobile and more flexibility than public transportation alone. These systems are attractive since they offer the potential to lower a user’s transportation costs; reduce the need for parking spaces in a community; improve overall air quality; and...

Shared Mobility in Low- and High-Income Regions

2022

Although shared and informal transport are not new concepts in low- and middle- income countries (LMICs), a variety of economic, environmental, and social forces are contributing to the growth of shared mobility in LMICs around the world. Shared mobility—the shared use of a vehicle, motorcycle, autorickshaw, minibus, scooter, bicycle, or other travel mode—is an innovative transportation strategy that enables users to have short-term access to a transportation mode. This paper documents key shared mobility and informal transport concepts, terms, and definitions around the world. The paper...

Mobility and the Sharing Economy: Potential to Overcome First- and Last-Mile Public Transit Connections

Shaheen, Susan, PhD
Chan, Nelson
2016

Shared mobility—the shared use of a motor vehicle, bicycle, or other mode—enables travelers to gain short-term access to transportation modes on an as-needed basis. The term “shared mobility” includes the modes of carsharing, personal vehicle sharing (peer-to-peer carsharing and fractional ownership), bikesharing, scooter sharing, traditional ridesharing, transportation network companies (or ridesourcing), and e-Hail (taxis). It can also include flexible transit services, including microtransit, which supplement fixed-route bus and rail services. Shared mobility has proliferated in global...

Ammonia as an Alternative Energy Storage Medium for Hydrogen Fuel Cells: Scientific and Technical Review for Near-Term Stationary Power Demonstration Projects, Final Report

Lipman, Tim
Shah, Nihar
2007

This report documents the research efforts of a task order under a research technical agreement between the California Department of Transportation (Caltrans) and the University of California, Berkeley (UC Berkeley). The focus of this research is to understand the scientific and technical aspects of the potential use of ammonia and other related carbon-free energy carriers for hydrogen fuel cell applications. Caltrans has a range of potential applications for fuel cell technology, including various field operations and for providing emergency backup power, power “demand response”...

The Benefits of Carpooling

Shaheen, Susan, PhD
Cohen, Adam, MCRP
Bayen, Alexander, PhD
2018

Carpooling allows travelers to share a ride to a common destination and can include several forms of sharing a ride, such as casual carpooling and real-time carpooling. Because carpooling reduces the number of automobiles needed by travelers, it is often associated with numerous societal benefits including:1) reductions in energy consumption and emissions, 2) congestion mitigation, and 3) reduced parking infrastructure demand. In recent years, economic, environmental, and social forces coupled with technological innovations are encouraging shared and pooled services. Shared mobility is...

Public Bikesharing and Modal Shift Behavior: A Comparative Study of Early Bikesharing Systems in North America

Shaheen, Susan, PhD
Martin, Elliot, PhD
Cohen, Adam
2013

Public bikesharing—the shared use of a bicycle fleet by the public—is an innovative mobility strategy that has recently emerged in major North American cities. Bikesharing systems typically position bicycles throughout an urban environment, among a network of docking stations, for immediate access. This paper discusses the modal shift that results from individuals participating in four public bikesharing systems in North America. The authors conducted an online survey (n =10,661 total sample), between November 2011 and January 2012, with members of four major bikesharing organizations (...

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 fueleconomy. Despite the benefits of a combined policy approach, these strategies are normally employed separately. Nevertheless, they have been linked occasionally, for instance in the electric 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...

Roundtrip Carsharing in New York City: An Evaluation of a Pilot Program and System Impacts

Martin, Elliot, PhD
Stocker, Adam
Nichols, Aqshems
Shaheen, Susan, PhD
2021

The study found that roundtrip carsharing in NYC mostly serves as a substitute for car rental, other personal vehicle modes, and personal vehicle ownership. The analysis showed that the broader pilot program had a modest impact on user behavior through carsharing (i.e., reduced vehicle ownership, reduced VMT, and mode shift). It also found that the pilot program likely expanded the membership base of carsharing to demographic cohorts that are traditionally underrepresented in carsharing populations (i.e., increased participation by lower education levels, lower household incomes, minority...