Environment

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...

Shared Mobility: The Potential of Ride Hailing and Pooling

Shaheen, Susan, PhD
2018

Shared mobility with pooled rides is the linchpin for leveraging vehicle automation and electrification to reduce congestion and emissions and to create livable urban communities. The sharing of rides is older than horse-and-buggy travel. Recent innovations make sharing easier, more convenient, and more efficient. Innovative mobility services premised on pooling can lower travel costs, mitigate congestion, and reduce greenhouse gas emissions. They also offer travelers more mobility choices between the traditional bookends of auto ownership and public transit. While the realm of shared...

Automated Vehicles, On-Demand Mobility and Environmental Impacts

Greenblatt, Jeffery
Shaheen, Susan, PhD
2015

We review the history, current developments, projected future trends and environmental impacts of automated vehicles (AVs) and on-demand mobility, and explore potential synergies. Many automobile manufacturers and Google plan to release AVs between 2017 and 2020, with potential benefits including increased safety, more efficient road use, increased driver productivity and energy savings. Estimates of AV energy use and greenhouse gas (GHG) emissions range from an ~80 % or greater decrease to a threefold increase; however, we argue that net decreases are likely. On-demand mobility services...

A Low-Carbon Fuel Standard for California Part 2: Policy Analysis

Farrell, Alexander E.
Sperling, Daniel
Brandt, A.R.
Eggert, A.
Farrell, A.E.
Haya, B.K.
Hughes, J
Jenkins, B.M.
Jones, A.D.
Kammen, D.M.
Knittel, C.R.
Melaina, M.W.
O'Hare, M.
Plevin, R.J.
Sperling, D.
2007

The Low Carbon Fuel Standard (LCFS) can play a major role in reducing greenhouse gas emissions and stimulating improvements in transportation fuel technologies so that California can meet its climate policy goals. In Part 1 of this study we evaluated the technical feasibility of achieving a 10 percent reduction in the carbon intensity (measured in gCO2e/MJ) of transportation fuels in California by 2020. We identified six scenarios based on a variety of different technologies that could meet or exceed this goal, and concluded that the goal was ambitious but attainable. In Part 2, we examine...

How Public Education on Ecodriving Can Reduce Both Fuel Use and Greenhouse Gas Emissions

Martin, Elliot W.
Chan, Nelson D.
Shaheen, Susan A.
2012

Ecodriving, the concept of changing driving behavior and vehicle maintenance to impact fuel consumption and greenhouse gas (GHG) emissions in existing vehicles, has gained recent prominence in North America. One ecodriving strategy involves public education through Internet-based information dissemination. This paper presents the results of a controlled stated-response study conducted from June to December 2010 with approximately 100 University of California, Berkeley faculty, staff, and students, assessing the effectiveness of static ecodriving web-based information. A comparison of the...