Sustainability

Automated Vehicle Technology Has the Potential to Smooth Traffic Flow and Reduce Greenhouse Gas Emissions

Almatrudi, Sulaiman
Parvate, Kanaad
Rothchild, Daniel
Vijay, Upadhi
Jang, Kathy
Alexandre Bayen
2022

In an ideal world, all cars along a congested roadway would travel at the same constant average speed; however, this is hardly the case. As soon as one driver brakes, trailing cars must also brake to compensate, leading to “stop and go” traffic waves. This unnecessary braking and accelerating increases fuel consumption (and greenhouse gas emissions) by as much as 67 percent.1 Fortunately, automated vehicles (AVs) — even Level 2 AVs2 which are commercially available today — have the potential to mitigate this problem. By accelerating less than a human would, an AV with flow smoothing...

Modifying Adaptive Cruise Control Systems for String Stable Stop-and -Go Wave Control

Wu, Fangyu
Carpio, Joy
Bunting, Matthew
Nice, Matthew
Work, Daniel
Sprinkle, Jonathan M.
Lee, Jonathan
Hornstein, Sharon
Alexandre Bayen
2024

This letter addresses the important issue of energy inefficiency and air pollution resulting from stop-and-go waves on highways by introducing a novel controller called the Attenuative Kerner's Model (AKM). The objective of AKM is to enhance an existing Adaptive Cruise Control (ACC) system to improve vehicle following in stop-and-go waves. It is designed as a hybrid controller that is compatible with a wide range of commercial vehicles equipped with ACC. The article demonstrates the local string stability of the controller. Next, it presents a comparative analysis of AKM against two...

Vehicle Ownership and Mode Use: The Challenge of Sustainability

Srinivasan, Sumeeta
Joan Walker
2009

The theme of this special issue is Vehicle Ownership and Mode Use—the Challenge of Sustainability. This topic was inspired by the increasing emphasis by society on sustainability, in general, and the role of transportation within this broader picture. Indeed, issues of climate change and energy needs are among the biggest challenges currently facing the transportation profession. The quest for sustainable travel has, for better or for worse, been aided recently by historically high fuel prices as well as economic struggles. Together these forces have led to a reduction...

The Power and Value of Green in Promoting Sustainable Transport Behavior

Gaker, David
Vautin, David
Vij, Akshay
Joan Walker
2011

While it is increasingly popular to broadcast information regarding environmental impact, little is known regarding the effects that this information has on human behavior. This research aims to provide insight into whether, and to what extent, presenting environmental attributes of transport alternatives influences individual transport decisions. We designed and conducted three experiments in which subjects (UC Berkeley undergraduates) were presented with hypothetical scenarios of transport decisions, including auto purchase choice, mode choice, and route choice. We analyzed their...

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

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

Revealing the Value of “Green” and the Small Group with a Big Heart in Transportation Mode Choice

Gaker, David
Joan Walker
2013

To address issues of climate change, people are more and more being presented with the greenhouse gas emissions associated with their alternatives. Statements of pounds or kilograms of CO2 are showing up in trip planners, car advertisements, and even restaurant menus under the assumption that this information influences behavior. This research contributes to the literature that investigates how travelers respond to such information. Our objective is to better understand the “value of green” or how much travelers are willing to pay in money in order to reduce the CO2 associated with their...

Quantitative Metrics of Stove Adoption Using Stove Use Monitors (SUMs)

Ruiz-Mercado, Ilse
Canuz, Eduardo
Joan Walker
Smith, Kirk R.
2013

The sustained use of cookstoves that are introduced to reduce fuel use or air pollution needs to be objectively monitored to verify the sustainability of these benefits. Quantifying stove adoption requires affordable tools, scalable methods and validated metrics of usage. We quantified the longitudinal patterns of chimney-stove use of 80 households in rural Guatemala, monitored with Stove Use Monitors (SUMs) during 32 months. We counted daily meals and days in use at each monitoring period and defined metrics like the percent stove-days in use (the fraction of days in use from all stoves...

Joint Planning of PEV Fast-Charging Network and Distributed PV Generation

Zhang, Hongcai
Scott Moura
Hu, Zechun
Qi, Wei
2017

Integration of plug-in electric vehicles (PEVs) with distributed renewable resources will decrease PEVs' well-to-wheels greenhouse gas emissions, promote renewable power adoption and defer power system investments. This paper proposes a multidisciplinary approach to jointly planning PEV fast-charging stations and distributed photovoltaic (PV) power plants on coupled transportation and power networks. First, we develop models of 1) PEV fast-charging stations; 2) highway transportation networks under PEV driving range constraints; 3) PV power plants with reactive power control. Then, we...

Quantified Traveler: Travel Feedback Meets the Cloud to Change Behavior

Sengupta, Raja
Joan Walker
2015

Halting climate change will require a concerted effort to reduce emissions from on-road vehicles. While significant progress has been made to improve vehicle efficiency and reduce CO 2 emissions, surface transportation accounted for half the increase in US green-house gas (GHG) emissions over the past two decades. Today, surface transportation accounts for 24 percent of all US emissions. Automobile improvements alone will not be sufficient to meet federal and state emissions targets; policy makers also need to identify solutions that reduce the demand for car travel. Information technology...

Quantified Traveler: Travel Feedback Meets the Cloud to Change Behavior

Sengupta, Raja
Joan Walker
2015

Halting climate change will require a concerted effort to reduce emissions from on-road vehicles. While significant progress has been made to improve vehicle efficiency and reduce CO 2 emissions, surface transportation accounted for half the increase in US greenhouse gas (GHG) emissions over the past two decades. Today, surface transportation accounts for 24 percent of all US emissions. Automobile improvements alone will not be sufficient to meet federal and state emissions targets; policy makers also need to identify solutions that reduce the demand for car travel. Information technology...