Environment

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...

Creating Markets for Green Biofuels: Measuring and Improving Environmental Performance

Turner, Brian T.
Plevin, Richard J.
O'Hare, Michael
Farrell, Alexander E.
2007

This study describes how some biofuels are produced, emphasizing agricultural production systems, and considers what is needed in order to measure and communicate environmental performance, and gives examples of how this might be done. We describe a set of seven uses of a Green Biofuels Index, from a wholly market-driven implementation through a set of increasingly intrusive regulatory approaches. We then present several case studies of specific biofuel production pathways using a lifecycle analysis of the inputs to feedstock production and processing, but excluding market-mediated effects...

Carsharing's Impact on Household Vehicle Holdings: Results from a North American Shared-Use Vehicle Survey

Martin, Elliot
Shaheen, Susan A.
Lidicker, Jeffrey
2010

Carsharing has grown considerably in North America during the past decade and has flourished within metropolitan regions across the United States and Canada. The result has been a new transportation landscape, which offers urban residents an alternative to automobility without carownership. As carsharing has expanded, there has been a growing demand to understand its environmental impacts. This paper presents the results of a North American carsharing member survey (N = 6,281). The authors establish a “before-and-after” analytical design with a focus oncarsharing’s impacts on household...

Advanced Air Mobility: Opportunities, Challenges, and Research needsfor the State of California (2023-2030)

Cohen, Adam
Shaheen, Susan, PhD
2024

Advanced air mobility (AAM) is a broad concept that enables consumers access to air mobility, goods delivery, and emergency services through an integrated and connected multimodal transportation network. AAM can provide short-range urban, suburban, and rural flights of about 50-miles and mid-range regional flights up to a several hundred miles. State law delegates responsibility for oversight in aviation primarily to the California Department of Transportation (Caltrans). This white paper presents an overview of the state of the market, such as the aircraft under development and forecast...

Shared Micromoblity Policy Toolkit: Docked and Dockless Bike and Scooter Sharing

Shaheen, Susan, PhD
Cohen, Adam
2019

Shared Micromobility – the shared use of a bicycle, scooter, or other low-speed mode – is an innovative transportation strategy that enables users to have short-term access to a mode of transportation on an as-needed basis. Shared micromobility includes various service models and transportation modes that meet the diverse needs of travelers, such as station-based bikesharing (a bicycle picked-up from and returned to any station or kiosk) and dockless bikesharing and scooter sharing (a bicycle or scooter picked up and returned to any location). Early documented impacts of shared...