Sustainability

Emerging Technologies for Higher Fuel Economy Automobile Standards

Tim Lipman
2017

Transportation systems contribute significantly to air pollution and ∼15% globally and ∼25% in the United States to emissions climate-changing gases. In the United States, the Corporate Average Fuel Economy (CAFE) standards for motor vehicles were significantly raised in 2012 for the first time in almost three decades. The standards now call for an average across manufacturers of 54.5 miles per gallon (mpg) for new passenger cars by 2025, or 163 grams per mile (g/mi) of greenhouse gas (GHG) emissions, and of 47 mpg (196 g/mi) by 2021. The light truck standards, which include minivans and...

Lifecycle Cost Assessment and Carbon Dioxide Emissions of Diesel, Natural Gas, Hybrid Electric, Fuel Cell Hybrid and Electric Transit Buses

Antti Lajunen
Tim Lipman
2016

This paper evaluates the lifecycle costs and carbon dioxide emissions of different types of city buses. The simulation models of the different powertrains were developed in the Autonomie vehicle simulation software. The carbon dioxide emissions were calculated both for the bus operation and for the fuel and energy pathways from well to tank. Two different operating environment case scenarios were used for the primary energy sources, which were Finland and California (USA). The fuel and energy pathways were selected appropriately in relation to the operating environment. The lifecycle costs...

A Systematic Review of Life Cycle Greenhouse Gas Intensity Values for Hydrogen Production Pathways

P Busch
A Kendall
Tim Lipman
2023

Hydrogen is a potential low-carbon energy carrier to replace fossil fuels, especially in industrial and transportation applications where decarbonization is particularly challenging. Hydrogen can be generated via several feedstocks and technology combinations (pathways) that result in different life cycle greenhouse gas emissions intensities, thus policies and investments intended to deploy hydrogen as a climate solution must differentiate among pathways. To collect and analyze current estimates of the life cycle greenhouse gas intensity of hydrogen pathways, a systematic scholarly...

Driving California’s Transportation Emissions to Zero

Austin Brown
Daniel Sperling
Bernadette Austin
J. R. DeShazo
Lew Fulton
Tim Lipman
Colin Murphy
Jean Daniel
Gil Tal
Carolyn Abrams
Debapriya Chakraborty
Daniel Coffee
Sina Dabag
Adam Davis
Mark Delucchi
Kelly Fleming
Kate Forest
Juan Carlos Garcia Sanchez
Susan Handy
Michael Hyland
Alan Jenn
Seth Karten
Blake Lane
Michael Mackinnon
Elliot Martin
Marshall Miller
Monica Ramirez-Ibarra
Stephen Ritchie
Sara Schremmer
Joshua Segui
Susan Shaheen
Andre Tok
Aditya Voleti
Julie Witcover
Allison Yang
2021

The purpose of this report is to provide a research-driven analysis of options that can put California on a pathway to achieve carbon-neutral transportation by 2045. The report comprises thirteen sections. Section 1 provides an overview of the major components of transportation systems and how those components interact. Section 2 discusses the impacts the COVID-19 pandemic has had on transportation. Section 3 discusses California’s current transportation-policy landscape. These three sections were previously published as a synthesis report. Section 4 analyzes the different carbon scenarios...

Carbon Neutrality Study 1:Driving California’s Transportation Emissions to Zero

Austin Brown
Kelly Fleming
Tim Lipman
Lew Fulton
Jean Daniel Saphores
Gil Tal
Colin Murphy
Susan Shaheen
Bernadette Austin
Juan Carlos Garcia Sanchez
Elliot Martin
Marshall Miller
Michael Hyland
Susan Handy
Mark Delucchi
Daniel Coffee
J. R. DeShazo
2020

The purpose of this study overall is to explore the policy pathways to achieve a zero carbon transportation system in California by 2045. The purpose of this synthesis report is to describe the existing state of knowledge and policy related to energy use and greenhouse gas (GHG) emissions in the transportation sector, especially in California. It is an interim product of the larger study, which will use this report as the baseline and policy context sections. The report comprises four sections. Section 1 provides an overview of the major components of transportation systems and how those...

Evaluation of Fuel Cell Auxiliary Power Units for Heavy-Duty Diesel Trucks

Christie-Joy Brodrick
Tim Lipman
Mohammad Farshchi
Nicholas P. Lutsey
Harry A. Dwyer
Daniel Sperling
William Gouse
Bruce Harris
Foy King
2002

A large number of heavy-duty trucks idle a significant amount. Heavy-duty line-haul truck engines idle about 20–40% of the time the engine is running, depending on season and operation. Drivers idle engines to power climate control devices (e.g., heaters and air conditioners) and sleeper compartment accessories (e.g., refrigerators, microwave ovens, and televisions) and to avoid start-up problems in cold weather. Idling increases air pollution and energy use, as well as wear and tear on engines. Efforts to reduce truck idling in the US have been sporadic, in part because it is widely...

Multi-stage Models for Dynamic Ride-Sharing in Taxi Services and Congestion Analysis

Quadrifoglio, Luca
Zhang, Cheng
Sun, Min-Ci
Maria Laura Delle Monache
Yeo, Yuneil
2024

This research introduces practical optimization model for implementing ride-sharing in taxi services and studies the effects of ride-sharing on the congestion status through the case study of Chicago. Ride-sharing combines trips into one ride-shared trip with the objective of maximizing the total mileage saving. This research proposes a multi-stage model to optimize rider matches, aiming to reduce the total travel distance and enhance the matching of multiple riders. To validate the effectiveness of the model, real taxi data from Chicago is used, demonstrating significant improvements in...

High Accuracy Location Based Services CostBenefit Study: Final Report

Goodliss, Adam
Manasseh, Christian
Ekambaram, Venkatesan
Raja Sengupta
Kanafani, Adib
Ramchandran, Kannan
2011

This report presents a benefit and cost study of a Cooperative High‐Accuracy LOcation (C‐HALO) service. A High Accuracy Location service should be ubiquitous and reliable as the GPS constellation. A survey of the literature on location services reveals a body of work on the benefits of a high accuracy location service. Focusing on road travel, benefits are estimated to be between $160-$320 billion dollars over slightly more than 20 years. The benefits arise from smoother traffic flow on the roads leading to reduced travel delays, and fewer accidents leading to reduced injuries and saved...

The Quantified Traveler: Using Personal Travel Data to Promote Sustainable Transport Behavior

Jariyasunant, Jerald
Carrel, Andre
Ekambaram, Venkatesan
Gaker, D. J.
Kote, Thejovardhana
Raja Sengupta
Joan Walker
2011

With the advent of ubiquitous mobile sensing and self-tracking groups, travel demand researchers have a unique opportunity to combine these two developments to improve the state of the art of travel diary collection. While the use of mobile phones and the inference of travel diaries from GPS and sensor data allows for lower-cost, longer surveys, we show how the self-tracking movement can be leveraged to interest people in participating over a longer period of time. By compiling personalized feedback and statistics on participants’ travel habits during the survey, we can provide the...

The Quantified Traveler: Using personal travel data to promote sustainable transport behavior

Jariyasunant, Jerald
Carrel, Andre
Ekambaram, Venkatesan
Gaker, D. J.
Kote, Thejovardhana
Raja Sengupta
Walker, Joan L.
2011

With the advent of ubiquitous mobile sensing and self-tracking groups, travel demand researchers have a unique opportunity to combine these two developments to improve the state of the art of travel diary collection. While the use of mobile phones and the inference of travel diaries from GPS and sensor data allows for lower-cost, longer surveys, we show how the self-tracking movement can be leveraged to interest people in participating over a longer period of time. By compiling personalized feedback and statistics on participants’ travel habits during the survey, we can provide the...