Research Projects

Project at a Glance

Project Status: complete

Report Published April 2017:

ARB Seminars:

Title: Modeling household vehicle and transportation choice and usage

Principal Investigator / Author(s): Mokhtarian, Patricia and David Rapson

Contractor: UC Davis and Yale University

Contract Number: 11-322

Research Program Area: Climate Change

Topic Areas: Behavioral Change, Mobile Sources & Fuels, Modeling, Sustainable Communities


The Assembly Bill (AB) 32 Scoping Plan points out that significant reductions in greenhouse gas (GHG) emissions from transportation are necessary to reach the Stateís GHG reduction goals for 2020 and beyond. ARB is already pursuing passenger vehicle related GHG emissions reductions through AB 1493 (Pavley, 2002), Senate Bill (SB) 375 (Steinberg, 2008), the Low Carbon Fuel Standard, the Advanced Clean Cars (LEV III) regulation, and various vehicle efficiency programs (such as the Tire Pressure Regulation). Additional research is needed to support the successful implementation of several of these programs, particularly SB 375 and Advanced Clean Cars.
Research to support SB 375 and Advanced Clean Cars should illuminate Californiansí motivations for, and barriers to, voluntarily adopting lower-emissions transportation behaviors, such as purchasing and using vehicles that are more efficient and/or use alternative fuels, and reducing vehicle miles traveled (VMT). In addition, this research will improve ARBís ability to forecast the future light-duty fleet, and associated emissions, and will also improve ARBís understanding of motivations for low-emissions transportation behavior (such as low vehicle ownership or low VMT) and consumer choices about what vehicle to buy and how much to drive. The project contains two major components that are designed to be complementary by providing insights into low emissions travel and consumer choices using different methodologies and datasets. Insights from the first component will help guide the modeling in the second.

The first major component of the proposed project will focus on understanding the factors that lead some Californians to a small transportation emissions footprint. It will identify the geographic and demographic characteristics of these low transportation emissions households. The second major component of the proposed project will focus on jointly modeling the consumer decision process about when to buy a vehicle, what type of vehicle to buy, and how much to drive the vehicle. This will allow for a more rigorous evaluation of the effects of policies that influence either the choice of vehicle or the usage of vehicles and provide insights into consumer valuation of different vehicle attributes. The results of this project will shed light on the effects of many policies to reduce emissions from the light duty fleet.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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